It seems that problem is not in horizon but in openstack_auth.
openstack_auth uses keystone v2.0 client without 'endpoint' parameter.
And openstack_auth uses 'endpoint' parameter as management_url, which in turn used by user.endpoint and session['region_endpoint'].
It seems that problem is not in horizon but in openstack_auth.
openstack_auth uses keystone v2.0 client without 'endpoint' parameter. 'region_ endpoint' ].
And openstack_auth uses 'endpoint' parameter as management_url, which in turn used by user.endpoint and session[