Save OPENSTACK_KEYSTONE_URL to horizon local_settings

OPENSTACK_KEYSTONE_URL is not saved to local_settings correctly,
this patch fixes this bug.

Change-Id: I4275f035be3d8ab013840d8b5e3f9a5e292a366b
Remove obsolete sahara keystone auth conf

Change-Id: I9005d99540572bd1e9251683b1e9cc6638afa7e7
Merge "Save OPENSTACK_KEYSTONE_URL to horizon local_settings"
Merge "Remove obsolete sahara keystone auth conf"