Fix log_config ensure absent

- In order to fix the switching between debug true/false
  ensure log_config option is absent, then it should be

Change-Id: I171d8838c2bd756fda4d2afd47c6d7da070adc23
Signed-off-by: Bogdan Dobrelya <bdobrelia@mirantis.com>
Merge "Fix log_config ensure absent"