tasks: rabbitmq_started: Signal rabbitmq-server init failures
tasks: rabbitmq_started: Signal rabbitmq-server init failures

It is important to know that rabbitmq-server was started properly
otherwise subsequent rabbitmq commands will fail. As such, we drop
the 'failed_when' statements and let the service module signal
potential failures.

Change-Id: Ib02a538f33fc6d7b21edbcbfe6c2a5bd06a21045

openstack/openstack-ansible-rabbitmq_server,openstack/openstack-ansible-rabbitmq_server