We are currently solving the following issue within our repository. Here is the issue text:
--- BEGIN ISSUE ---
On creating a plan, "Berlin" may be selected as district
"Berlin" is part of the dropdown in the vorhaben create and update form

@MagdaN should i add this issue to the whiteboard or taiga, too?

--- END ISSUE ---

Below are some code segments, each from a relevant file. One or more of these files may contain bugs.
--- BEGIN FILES ---
Path: `meinberlin/apps/plans/models.py`
Content:
```
1 from ckeditor.fields import RichTextField
2 from django.conf import settings
3 from django.core.urlresolvers import reverse
4 from django.db import models
5 from django.utils.translation import ugettext_lazy as _
6 
7 from adhocracy4 import transforms
8 from adhocracy4.maps import fields as map_fields
9 from adhocracy4.models.base import UserGeneratedContentModel
10 from adhocracy4.projects import models as project_models
11 from meinberlin.apps.maps.models import MapPreset
12 
13 STATUS_TODO = 0
14 STATUS_PLANNING = 1
15 STATUS_IMPLEMENTATION = 2
16 STATUS_DONE = 3
17 STATUS_STOPPED = 4
18 
19 PARTICIPATION_NO = 0
20 PARTICIPATION_YES = 1
21 PARTICIPATION_UNDECIDED = 2
22 
23 
24 class Plan(UserGeneratedContentModel):
25     title = models.CharField(max_length=120, verbose_name=_('Title'))
26     organisation = models.ForeignKey(
27         settings.A4_ORGANISATIONS_MODEL,
28         on_delete=models.CASCADE)
29     project = models.ForeignKey(project_models.Project, blank=True, null=True)
30     point = map_fields.PointField(
31         verbose_name=_('Where can the plan be located on a map?'),
32         help_text=_('Click inside marked area on the map to set a marker. '
33                     'Drag and drop the marker to change its place. '
34                     'Alternatively you can use the search field to search '
35                     'for an address.'))
36     point_label = models.CharField(
37         blank=True,
38         default='',
39         max_length=255,
40         verbose_name=_('Label of the location'),
41         help_text=_('This could be an address or the name of a landmark.'),
42     )
43     district = models.ForeignKey(
44         MapPreset,
45         limit_choices_to={'category__name': 'Berlin'})
46     contact = models.TextField(max_length=255, verbose_name=_('Contact'))
47     cost = models.PositiveIntegerField(blank=True, null=True,
48                                        verbose_name=_('Cost'))
49     description = RichTextField(verbose_name=_('Description'), blank=True)
50     category = models.CharField(max_length=255, verbose_name=_('Type of plan'))
51     status = models.SmallIntegerField(choices=(
52         (STATUS_TODO, _('Idea')),
53         (STATUS_PLANNING, _('Planning')),
54         (STATUS_IMPLEMENTATION, _('Implementation')),
55         (STATUS_DONE, _('Done')),
56         (STATUS_STOPPED, _('Stopped')),
57     ))
58     participation = models.SmallIntegerField(choices=(
59         (PARTICIPATION_YES, _('Yes')),
60         (PARTICIPATION_NO, _('No')),
61         (PARTICIPATION_UNDECIDED, _('Still undecided')),
62     ))
63 
64     class Meta:
65         ordering = ['-created']
66 
67     @property
68     def reference_number(self):
69         return '{:d}-{:05d}'.format(self.created.year, self.pk)
70 
71     def __str__(self):
72         return self.title
73 
74     def get_absolute_url(self):
75         return reverse('meinberlin_plans:plan-detail',
76                        kwargs=dict(pk=self.pk, year=self.created.year))
77 
78     def save(self, *args, **kwargs):
79         self.description = transforms.clean_html_field(self.description)
80         super().save(*args, **kwargs)
81
```
--- END FILES ---

Please first localize the bug based on the issue statement, and then generate a patch according to the `git diff` format fenced by three backticks.

Here is an example:

```diff
diff --git a/examples/server_async.py b/examples/server_async.py
--- a/examples/server_async.py
+++ b/examples/server_async.py
@@ -313,4 +313,4 @@
 
 
 if __name__ == "__main__":
-    asyncio.run(run_async_server("."), debug=True)
+    asyncio.run(run_async_server(), debug=True)
diff --git a/examples/server_sync.py b/examples/server_sync.py
--- a/examples/server_sync.py
+++ b/examples/server_sync.py
@@ -313,5 +313,5 @@
 
 
 if __name__ == "__main__":
-    server = run_sync_server(".")
+    server = run_sync_server()
     server.shutdown()

```

diff --git a/meinberlin/apps/plans/models.py b/meinberlin/apps/plans/models.py
--- a/meinberlin/apps/plans/models.py
+++ b/meinberlin/apps/plans/models.py
@@ -2,6 +2,7 @@
 from django.conf import settings
 from django.core.urlresolvers import reverse
 from django.db import models
+from django.db.models import Q
 from django.utils.translation import ugettext_lazy as _
 
 from adhocracy4 import transforms
@@ -42,7 +43,7 @@
     )
     district = models.ForeignKey(
         MapPreset,
-        limit_choices_to={'category__name': 'Berlin'})
+        limit_choices_to=Q(category__name='Berlin') & ~Q(name='Berlin'))
     contact = models.TextField(max_length=255, verbose_name=_('Contact'))
     cost = models.PositiveIntegerField(blank=True, null=True,
                                        verbose_name=_('Cost'))

{"golden_diff": "diff --git a/meinberlin/apps/plans/models.py b/meinberlin/apps/plans/models.py\n--- a/meinberlin/apps/plans/models.py\n+++ b/meinberlin/apps/plans/models.py\n@@ -2,6 +2,7 @@\n from django.conf import settings\n from django.core.urlresolvers import reverse\n from django.db import models\n+from django.db.models import Q\n from django.utils.translation import ugettext_lazy as _\n \n from adhocracy4 import transforms\n@@ -42,7 +43,7 @@\n     )\n     district = models.ForeignKey(\n         MapPreset,\n-        limit_choices_to={'category__name': 'Berlin'})\n+        limit_choices_to=Q(category__name='Berlin') & ~Q(name='Berlin'))\n     contact = models.TextField(max_length=255, verbose_name=_('Contact'))\n     cost = models.PositiveIntegerField(blank=True, null=True,\n                                        verbose_name=_('Cost'))\n", "issue": "On creating a plan, \"Berlin\" may be selected as district\n\"Berlin\" is part of the dropdown in the vorhaben create and update form\r\n\r\n@MagdaN should i add this issue to the whiteboard or taiga, too?\n", "before_files": [{"content": "from ckeditor.fields import RichTextField\nfrom django.conf import settings\nfrom django.core.urlresolvers import reverse\nfrom django.db import models\nfrom django.utils.translation import ugettext_lazy as _\n\nfrom adhocracy4 import transforms\nfrom adhocracy4.maps import fields as map_fields\nfrom adhocracy4.models.base import UserGeneratedContentModel\nfrom adhocracy4.projects import models as project_models\nfrom meinberlin.apps.maps.models import MapPreset\n\nSTATUS_TODO = 0\nSTATUS_PLANNING = 1\nSTATUS_IMPLEMENTATION = 2\nSTATUS_DONE = 3\nSTATUS_STOPPED = 4\n\nPARTICIPATION_NO = 0\nPARTICIPATION_YES = 1\nPARTICIPATION_UNDECIDED = 2\n\n\nclass Plan(UserGeneratedContentModel):\n    title = models.CharField(max_length=120, verbose_name=_('Title'))\n    organisation = models.ForeignKey(\n        settings.A4_ORGANISATIONS_MODEL,\n        on_delete=models.CASCADE)\n    project = models.ForeignKey(project_models.Project, blank=True, null=True)\n    point = map_fields.PointField(\n        verbose_name=_('Where can the plan be located on a map?'),\n        help_text=_('Click inside marked area on the map to set a marker. '\n                    'Drag and drop the marker to change its place. '\n                    'Alternatively you can use the search field to search '\n                    'for an address.'))\n    point_label = models.CharField(\n        blank=True,\n        default='',\n        max_length=255,\n        verbose_name=_('Label of the location'),\n        help_text=_('This could be an address or the name of a landmark.'),\n    )\n    district = models.ForeignKey(\n        MapPreset,\n        limit_choices_to={'category__name': 'Berlin'})\n    contact = models.TextField(max_length=255, verbose_name=_('Contact'))\n    cost = models.PositiveIntegerField(blank=True, null=True,\n                                       verbose_name=_('Cost'))\n    description = RichTextField(verbose_name=_('Description'), blank=True)\n    category = models.CharField(max_length=255, verbose_name=_('Type of plan'))\n    status = models.SmallIntegerField(choices=(\n        (STATUS_TODO, _('Idea')),\n        (STATUS_PLANNING, _('Planning')),\n        (STATUS_IMPLEMENTATION, _('Implementation')),\n        (STATUS_DONE, _('Done')),\n        (STATUS_STOPPED, _('Stopped')),\n    ))\n    participation = models.SmallIntegerField(choices=(\n        (PARTICIPATION_YES, _('Yes')),\n        (PARTICIPATION_NO, _('No')),\n        (PARTICIPATION_UNDECIDED, _('Still undecided')),\n    ))\n\n    class Meta:\n        ordering = ['-created']\n\n    @property\n    def reference_number(self):\n        return '{:d}-{:05d}'.format(self.created.year, self.pk)\n\n    def __str__(self):\n        return self.title\n\n    def get_absolute_url(self):\n        return reverse('meinberlin_plans:plan-detail',\n                       kwargs=dict(pk=self.pk, year=self.created.year))\n\n    def save(self, *args, **kwargs):\n        self.description = transforms.clean_html_field(self.description)\n        super().save(*args, **kwargs)\n", "path": "meinberlin/apps/plans/models.py"}], "after_files": [{"content": "from ckeditor.fields import RichTextField\nfrom django.conf import settings\nfrom django.core.urlresolvers import reverse\nfrom django.db import models\nfrom django.db.models import Q\nfrom django.utils.translation import ugettext_lazy as _\n\nfrom adhocracy4 import transforms\nfrom adhocracy4.maps import fields as map_fields\nfrom adhocracy4.models.base import UserGeneratedContentModel\nfrom adhocracy4.projects import models as project_models\nfrom meinberlin.apps.maps.models import MapPreset\n\nSTATUS_TODO = 0\nSTATUS_PLANNING = 1\nSTATUS_IMPLEMENTATION = 2\nSTATUS_DONE = 3\nSTATUS_STOPPED = 4\n\nPARTICIPATION_NO = 0\nPARTICIPATION_YES = 1\nPARTICIPATION_UNDECIDED = 2\n\n\nclass Plan(UserGeneratedContentModel):\n    title = models.CharField(max_length=120, verbose_name=_('Title'))\n    organisation = models.ForeignKey(\n        settings.A4_ORGANISATIONS_MODEL,\n        on_delete=models.CASCADE)\n    project = models.ForeignKey(project_models.Project, blank=True, null=True)\n    point = map_fields.PointField(\n        verbose_name=_('Where can the plan be located on a map?'),\n        help_text=_('Click inside marked area on the map to set a marker. '\n                    'Drag and drop the marker to change its place. '\n                    'Alternatively you can use the search field to search '\n                    'for an address.'))\n    point_label = models.CharField(\n        blank=True,\n        default='',\n        max_length=255,\n        verbose_name=_('Label of the location'),\n        help_text=_('This could be an address or the name of a landmark.'),\n    )\n    district = models.ForeignKey(\n        MapPreset,\n        limit_choices_to=Q(category__name='Berlin') & ~Q(name='Berlin'))\n    contact = models.TextField(max_length=255, verbose_name=_('Contact'))\n    cost = models.PositiveIntegerField(blank=True, null=True,\n                                       verbose_name=_('Cost'))\n    description = RichTextField(verbose_name=_('Description'), blank=True)\n    category = models.CharField(max_length=255, verbose_name=_('Type of plan'))\n    status = models.SmallIntegerField(choices=(\n        (STATUS_TODO, _('Idea')),\n        (STATUS_PLANNING, _('Planning')),\n        (STATUS_IMPLEMENTATION, _('Implementation')),\n        (STATUS_DONE, _('Done')),\n        (STATUS_STOPPED, _('Stopped')),\n    ))\n    participation = models.SmallIntegerField(choices=(\n        (PARTICIPATION_YES, _('Yes')),\n        (PARTICIPATION_NO, _('No')),\n        (PARTICIPATION_UNDECIDED, _('Still undecided')),\n    ))\n\n    class Meta:\n        ordering = ['-created']\n\n    @property\n    def reference_number(self):\n        return '{:d}-{:05d}'.format(self.created.year, self.pk)\n\n    def __str__(self):\n        return self.title\n\n    def get_absolute_url(self):\n        return reverse('meinberlin_plans:plan-detail',\n                       kwargs=dict(pk=self.pk, year=self.created.year))\n\n    def save(self, *args, **kwargs):\n        self.description = transforms.clean_html_field(self.description)\n        super().save(*args, **kwargs)\n", "path": "meinberlin/apps/plans/models.py"}]}