Remove deprecated address from keystone spec

When I57b8469fb816c37c9d6a285c07796f685b121a90 (Remove deprecated
parameter 'address') was merged openstack_keystone_spec.rb broke.
This change removes the use of the deprecated 'address'.

Change-Id: Ib6d74bfc0d13f5c13f523d5d98b4aea60cc4adaf
(cherry picked from commit 1bd3442a946f81101ff60dc45ba996fa3d5bb4e2)