Remove *_url inisets since now come from catalog

Another proposed change fetches endpoints from the Keystone catalog as
long as the *_url opts are not present. This change will make Trove on
DevStack use the catalog.

Note: This must merge after https://review.openstack.org/68015.

Change-Id: I397254e72823ab7c7b28014d4fa18e2cefb79e6d
Closes-Bug: #1222891
Merge "Remove *_url inisets since now come from catalog"