Updated openstack/openstack
Project: openstack/keystone  d618377855b472a49dc9f11433c0e5de47f6ab6f

Update control_exchange value in keystone.conf

The control_exchange comes from oslo and is set to 'openstack' by
default. This should be overridden by the projects that use
oslo.messaging, since projects should be placing notifications
on project specific exchanges.

Nova performs the override in the same manner:
https://github.com/openstack/nova/blob/master/nova/config.py#L33
https://github.com/openstack/nova/blob/master/nova/rpc.py#L77

Change-Id: Ifcc43dcccaa9d56e03922ce8cf0bf7fb8e93bdcc