Update the management url for every fetched token

management_url was originally set once and never changed so that when
specifying an endpoint it wasn't later overridden by the service
catalog. This behaviour would prevent the management_url from being
updated when the client was reauthenticated.

Change-Id: I2fa41e2ae1b853bbb254698cf94b9314eb0f0903
Closes-bug: 1252927
Revert "Merge "Avoid returning stale token via auth_token property""

This reverts commit b89d28663ed181e1df56ada271931891a4c77f67, reversing
changes made to 8a0732e262cd9de508399eabeb705b681c2503c0.

This change was causing gate issues. It breaks a few Keystone tests in
test_keystoneclient.py.

Change-Id: I8de6988c554a1359c04ce2d1a8c4707dee7c3782
Merge "Update the management url for every fetched token"