We are currently solving the following issue within our repository. Here is the issue text:
--- BEGIN ISSUE ---
runbot 9.0 red due to letsencrypt?
Hi,

It seems the 9.0 branch is red on runbot due to the letsencrypt module?

```
Call of self.pool.get('letsencrypt').cron(cr, uid, *()) failed in Job 2
Traceback (most recent call last):
  File "/srv/openerp/instances/openerp-oca-runbot/parts/odoo-extra/runbot/static/build/3148182-9-0-209efa/openerp/addons/base/ir/ir_cron.py", line 129, in _callback
    getattr(model, method_name)(cr, uid, *args)
  File "/srv/openerp/instances/openerp-oca-runbot/parts/odoo-extra/runbot/static/build/3148182-9-0-209efa/openerp/api.py", line 250, in wrapper
    return old_api(self, *args, **kwargs)
  File "/srv/openerp/instances/openerp-oca-runbot/parts/odoo-extra/runbot/static/build/3148182-9-0-209efa/openerp/api.py", line 354, in old_api
    result = method(recs, *args, **kwargs)
  File "/srv/openerp/instances/openerp-oca-runbot/parts/odoo-extra/runbot/static/build/3148182-9-0-209efa/openerp/addons/letsencrypt/models/letsencrypt.py", line 151, in cron
    account_key, csr, acme_challenge, log=_logger, CA=DEFAULT_CA)
  File "/srv/openerp/instances/openerp-oca-runbot/sandbox/local/lib/python2.7/site-packages/acme_tiny.py", line 104, in get_crt
    raise ValueError("Error requesting challenges: {0} {1}".format(code, result))
ValueError: Error requesting challenges: 400 {
  "type": "urn:acme:error:malformed",
  "detail": "Error creating new authz :: Invalid character in DNS name",
  "status": 400
}
```

@hbrunn 


--- END ISSUE ---

Below are some code segments, each from a relevant file. One or more of these files may contain bugs.
--- BEGIN FILES ---
Path: `letsencrypt/__openerp__.py`
Content:
```
1 # -*- coding: utf-8 -*-
2 # © 2016 Therp BV <http://therp.nl>
3 # License AGPL-3.0 or later (http://www.gnu.org/licenses/agpl.html).
4 {
5     "name": "Let's encrypt",
6     "version": "9.0.1.0.0",
7     "author": "Therp BV,"
8               "Tecnativa,"
9               "Odoo Community Association (OCA)",
10     "license": "AGPL-3",
11     "category": "Hidden/Dependency",
12     "summary": "Request SSL certificates from letsencrypt.org",
13     "depends": [
14         'base',
15     ],
16     "data": [
17         "data/ir_config_parameter.xml",
18         "data/ir_cron.xml",
19     ],
20     "post_init_hook": 'post_init_hook',
21     "installable": True,
22     "external_dependencies": {
23         'bin': [
24             'openssl',
25         ],
26         'python': [
27             'acme_tiny',
28             'IPy',
29         ],
30     },
31 }
32
```
--- 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/letsencrypt/__openerp__.py b/letsencrypt/__openerp__.py
--- a/letsencrypt/__openerp__.py
+++ b/letsencrypt/__openerp__.py
@@ -16,6 +16,7 @@
     "data": [
         "data/ir_config_parameter.xml",
         "data/ir_cron.xml",
+        "demo/ir_cron.xml",
     ],
     "post_init_hook": 'post_init_hook',
     "installable": True,

{"golden_diff": "diff --git a/letsencrypt/__openerp__.py b/letsencrypt/__openerp__.py\n--- a/letsencrypt/__openerp__.py\n+++ b/letsencrypt/__openerp__.py\n@@ -16,6 +16,7 @@\n     \"data\": [\n         \"data/ir_config_parameter.xml\",\n         \"data/ir_cron.xml\",\n+        \"demo/ir_cron.xml\",\n     ],\n     \"post_init_hook\": 'post_init_hook',\n     \"installable\": True,\n", "issue": "runbot 9.0 red due to letsencrypt?\nHi,\n\nIt seems the 9.0 branch is red on runbot due to the letsencrypt module?\n\n```\nCall of self.pool.get('letsencrypt').cron(cr, uid, *()) failed in Job 2\nTraceback (most recent call last):\n  File \"/srv/openerp/instances/openerp-oca-runbot/parts/odoo-extra/runbot/static/build/3148182-9-0-209efa/openerp/addons/base/ir/ir_cron.py\", line 129, in _callback\n    getattr(model, method_name)(cr, uid, *args)\n  File \"/srv/openerp/instances/openerp-oca-runbot/parts/odoo-extra/runbot/static/build/3148182-9-0-209efa/openerp/api.py\", line 250, in wrapper\n    return old_api(self, *args, **kwargs)\n  File \"/srv/openerp/instances/openerp-oca-runbot/parts/odoo-extra/runbot/static/build/3148182-9-0-209efa/openerp/api.py\", line 354, in old_api\n    result = method(recs, *args, **kwargs)\n  File \"/srv/openerp/instances/openerp-oca-runbot/parts/odoo-extra/runbot/static/build/3148182-9-0-209efa/openerp/addons/letsencrypt/models/letsencrypt.py\", line 151, in cron\n    account_key, csr, acme_challenge, log=_logger, CA=DEFAULT_CA)\n  File \"/srv/openerp/instances/openerp-oca-runbot/sandbox/local/lib/python2.7/site-packages/acme_tiny.py\", line 104, in get_crt\n    raise ValueError(\"Error requesting challenges: {0} {1}\".format(code, result))\nValueError: Error requesting challenges: 400 {\n  \"type\": \"urn:acme:error:malformed\",\n  \"detail\": \"Error creating new authz :: Invalid character in DNS name\",\n  \"status\": 400\n}\n```\n\n@hbrunn \n\n", "before_files": [{"content": "# -*- coding: utf-8 -*-\n# \u00a9 2016 Therp BV <http://therp.nl>\n# License AGPL-3.0 or later (http://www.gnu.org/licenses/agpl.html).\n{\n    \"name\": \"Let's encrypt\",\n    \"version\": \"9.0.1.0.0\",\n    \"author\": \"Therp BV,\"\n              \"Tecnativa,\"\n              \"Odoo Community Association (OCA)\",\n    \"license\": \"AGPL-3\",\n    \"category\": \"Hidden/Dependency\",\n    \"summary\": \"Request SSL certificates from letsencrypt.org\",\n    \"depends\": [\n        'base',\n    ],\n    \"data\": [\n        \"data/ir_config_parameter.xml\",\n        \"data/ir_cron.xml\",\n    ],\n    \"post_init_hook\": 'post_init_hook',\n    \"installable\": True,\n    \"external_dependencies\": {\n        'bin': [\n            'openssl',\n        ],\n        'python': [\n            'acme_tiny',\n            'IPy',\n        ],\n    },\n}\n", "path": "letsencrypt/__openerp__.py"}], "after_files": [{"content": "# -*- coding: utf-8 -*-\n# \u00a9 2016 Therp BV <http://therp.nl>\n# License AGPL-3.0 or later (http://www.gnu.org/licenses/agpl.html).\n{\n    \"name\": \"Let's encrypt\",\n    \"version\": \"9.0.1.0.0\",\n    \"author\": \"Therp BV,\"\n              \"Tecnativa,\"\n              \"Odoo Community Association (OCA)\",\n    \"license\": \"AGPL-3\",\n    \"category\": \"Hidden/Dependency\",\n    \"summary\": \"Request SSL certificates from letsencrypt.org\",\n    \"depends\": [\n        'base',\n    ],\n    \"data\": [\n        \"data/ir_config_parameter.xml\",\n        \"data/ir_cron.xml\",\n        \"demo/ir_cron.xml\",\n    ],\n    \"post_init_hook\": 'post_init_hook',\n    \"installable\": True,\n    \"external_dependencies\": {\n        'bin': [\n            'openssl',\n        ],\n        'python': [\n            'acme_tiny',\n            'IPy',\n        ],\n    },\n}\n", "path": "letsencrypt/__openerp__.py"}]}