Change Ieff5a6cdd1ad352a9731d46785802e8c36adcdd1 introduced an
uncomplete fix when trying to fix the auth_url.
Given the case that a auth url already has a version included, an extra
version was added. This leads to messages in the keystone.log that
horizon is trying to authenticate with "POST /v3/v3/auth/tokens
HTTP/1.1".
Use urlparse correctly and also add a testcase for fix_auth_url_version().
Change-Id: I80fb310d95e8fdab1212fc5b092a37fd7b26a37a
Closes-Bug: 1508421