Configure RabbitMQ connection for Keystone

Keystone uses rabbitmq for user and tenant related notifications
and telemetry reporting.

Reordering the priorities due to ensure that Keystone is now listed
after RabbitMQ on the barclamp overview page.
Merge pull request #233 from dirkmueller/master

Configure RabbitMQ connection for Keystone
Use admin_URL for HA mode
Merge pull request #234 from dirkmueller/master

Setup admin_auth_URL also in HA mode