Don't restart rabbitmq via service in zabbix

In HA environments we manage rabbitmq via pacemaker so restarting
it via "service" won't work correctly.
Also, during deployment we can enable plugins before starting
rabbitmq service.

Change-Id: I6e0eeb9147801a430b73fdb00fa106b8d79c9476
Closes-bug: #1350853
Merge "Don't restart rabbitmq via service in zabbix"