If --os-auth-url is not provided, then assume auth is not enabled. However,
if --os-password or --os-auth-token is provided, then use default auth URL
if it is not provided.
Change-Id: Iaba14949e1b507f440b1609eb2d58eb6b6399f1d
Closes-Bug: #1503915
(cherry picked from commit e9b8e75b72)