The only services in OpenStack that have dedicated admin REST APIs
that actually enforce different permissions at the API level are
keystone and swift. Assuming there is a dedicated admin endpoint is an
artifical construct.
Change the default for the admin_info to be the normal public url. For
sites that really want 2 different values here, they can have it, but
default to the simpler thing.
Change-Id: I92efc4639d37cb2736bae7e40707a853f1e72be6
95550a5095