install-guide: fix output of rabbitmqctl outputs
install-guide: fix output of rabbitmqctl outputs

Change-Id: I277903bc083cf72a07a4846169bbf38012b9184f
Implements: blueprint installguide-liberty

AlekhyaMallina-Vedams/openstack-manuals,AlekhyaMallina-Vedams/openstack-manuals,kairoaraujo/openstack-manuals,openstack/openstack-manuals,kairoaraujo/openstack-manuals,AlekhyaMallina-Vedams/openstack-manuals,Akasurde/openstack-manuals,Akasurde/openstack-manuals,openstack/openstack-manuals,openstack/openstack-manuals,openstack/openstack-manuals