Comment 4 for bug 1633429

Got reproduce in https://product-ci.infra.mirantis.net/job/9.x.system_test.ubuntu.bonding_ha/120/console
at cleanup after passed network connectivity check at removing security group.
neutron-server contains several tracebacks after returning 500 err code:

2016-11-11 05:05:55.388 19010 ERROR neutron.api.v2.resource File "/usr/lib/python2.7/dist-packages/MySQLdb/connections.py", line 206, in __init__
2016-11-11 05:05:55.388 19010 ERROR neutron.api.v2.resource super(Connection, self).__init__(*args, **kwargs2)
2016-11-11 05:05:55.388 19010 ERROR neutron.api.v2.resource DBConnectionError: (_mysql_exceptions.OperationalError) (2013, "Lost connection to MySQL server at 'reading initial communication packet', system error: 0") [SQL: u'SE
LECT 1']