Updated openstack/openstack
Project: openstack/nova  4fb6c12fba7eed3057a2d2e6e8ea9a86d9084302

objects: Make use of utils.convert_version_to_tuple()

Make use of the convert_version_to_tuple() utility in objects that had
inlined an implementation of the same thing.

Change-Id: If48df452baa79eeb52218fcbad0e388edf8fd416