Failed nailgun_performance_tests

[Artur Kaszuba]

Test nailgun_performance_tests fails on fuel-ci ends with error:

E AppError: Bad response: 500 Internal Server Error (not 200 OK or 3xx redirect for http://localhost/api/nodegroups/)
E 'Traceback (most recent call last):\n File "/home/jenkins/workspace/nailgun_performance_tests/nailgun/nailgun/api/v1/handlers/base.py", line 282, in content_json\n resp = func(cls, *args, **kwargs)\n File "/home/jenkins/workspace/nailgun_performance_tests/nailgun/nailgun/api/v1/handlers/base.py", line 448, in POST\n new_obj = self.collection.create(data)\n
...
================= 1653 tests deselected by "-m 'performance'" ==================
 3 failed, 43 passed, 1 skipped, 1653 deselected, 1 pytest-warnings in 1533.27 seconds
ERROR: InvocationError: '/home/jenkins/workspace/nailgun_performance_tests/nailgun/.tox/py26/bin/py.test -vv --cleandb --junit-xml /home/jenkins/workspace/nailgun_performance_tests/nailgun.xml -m performance nailgun/test'

Jenkins job: https://ci.fuel-infra.org/job/nailgun_performance_tests/
Example log: https://ci.fuel-infra.org/job/nailgun_performance_tests/369/console