With the current code, OS_TENANT_NAME will take precednece over
--os-project-name beause OS_TENANT_NAME gets early-moved to
config['auth']['project_name'], then when the argparse value gets put
into config['project_name'] the auth fixing sees auth['project_name']
and thinks it should win.
Change-Id: I97084ea221eb963f14d98cf550a04bbd5c7d954c