Comment 5 for bug 1652584

The issue has been reproduced again on another env.
So I've got more readable error message:

TASK [Systemd loads fresh units] ***********************************************
task path: /root/mos_mu/playbooks/tasks/update_9x_fuel.yml:9
An exception occurred during task execution. The full traceback is:
Traceback (most recent call last):
  File "/usr/lib/python2.7/site-packages/ansible/executor/task_executor.py", line 120, in run
    else:
  File "/usr/lib/python2.7/site-packages/ansible/executor/task_executor.py", line 379, in _execute
    return dict(changed=False, skipped=True, skip_reason='Conditional check failed', _ansible_no_log=self._play_context.no_log)
  File "/usr/lib/python2.7/site-packages/ansible/executor/task_executor.py", line 596, in _get_connection
    return async_result
  File "/usr/lib/python2.7/site-packages/ansible/plugins/__init__.py", line 331, in get
  File "/usr/lib/python2.7/site-packages/ansible/plugins/connection/__init__.py", line 92, in __init__
    shell_filename = os.path.basename(self._play_context.executable)
AttributeError: 'PlayContext' object has no attribute 'executable'
fatal: [nailgun.test.domain.local]: FAILED! => {"failed": true, "msg": "Unexpected failure during module execution.", "stdout": ""}