Comment 2 for bug 1793813

This is affecting queens as well
ii magnum-api 6.1.0-0ubuntu1~cloud0 all OpenStack containers as a service
ii magnum-common 6.1.0-0ubuntu1~cloud0 all OpenStack containers as a service - API server
ii magnum-conductor 6.1.0-0ubuntu1~cloud0 all OpenStack containers as a service - conductor
ii python-magnum 6.1.0-0ubuntu1~cloud0 all OpenStack containers as a service - Python library

2018-10-22 09:17:38.029 4373 ERROR wsme.api [req-eac33901-0e82-48aa-aa15-9e1a491ee393 - - - - -] Server-side error: "'NoneType' object has no attribute 'replace'". Detail:
Traceback (most recent call last):

  File "/usr/lib/python2.7/dist-packages/wsmeext/pecan.py", line 84, in callfunction
    result = f(self, *args, **kwargs)

  File "/usr/lib/python2.7/dist-packages/magnum/api/controllers/v1/cluster_template.py", line 306, in get_all
    action='clustertemplate:get_all')

  File "/usr/lib/python2.7/dist-packages/magnum/common/policy.py", line 100, in enforce
    add_policy_attributes(target)

  File "/usr/lib/python2.7/dist-packages/magnum/common/policy.py", line 110, in add_policy_attributes
    trustee_domain_id = admin_osc.keystone().trustee_domain_id

  File "/usr/lib/python2.7/dist-packages/magnum/common/keystone.py", line 179, in trustee_domain_id
    access = self.domain_admin_auth.get_access(

  File "/usr/lib/python2.7/dist-packages/magnum/common/keystone.py", line 145, in domain_admin_auth
    auth_url=self.auth_url,

  File "/usr/lib/python2.7/dist-packages/magnum/common/keystone.py", line 47, in auth_url
    return CONF[ksconf.CFG_LEGACY_GROUP].auth_uri.replace('v2.0', 'v3')

AttributeError: 'NoneType' object has no attribute 'replace'