Adding qpid support to glance

Moving all mq related parameters under default["openstack"]["image"]["mq"]
so that other mq options can be added under it. Eventually, all rabbit
options will be brought under it. Bumped up version to 7.1.0

Implements: blueprint qpid-activemq-support

Change-Id: Ie0ed02a9262136c208d88d05f2431ff351e2edb2
Relax the dependency on openstack-identity to the 7.x series

openstack-identity is now on 7.2.0, which doesn't get picked up because of the
strict dependency of the 7.0.x series.

Change-Id: If374c256fbe15d6bc5f4eb19fd800eacd87a0f7a