Updated openstack/openstack
Project: openstack-dev/devstack  3f52e5ef742be9451b408b0a2f30293b14ade139
null
Default RABBIT_HOST to be the SERVICE_HOST.

Using localhost for RABBIT_HOST can cause problems - particularly
on systems where IPv6 is partially broken and localhost resolves
to an IPv6 address.

The service should logically be running on SERVICE_HOST unless
otherwise overridden.

Change-Id: I6efb71b8b95174770066f38403d5d428ec88c3b6