Creating an RBD without features causes an error

2017-07-20 16:46:19,903 1506 mod_wsgi INFO requests.packages.urllib3.connectionpool#_new_conn - Starting new HTTP connection (1): deepsea-ci-1.oa.suse.de
2017-07-20 16:46:19,911 1506 mod_wsgi INFO deepsea#_login - Salt API login successful
2017-07-20 16:46:21,771 1502 mod_wsgi INFO requests.packages.urllib3.connectionpool#_new_conn - Starting new HTTP connection (1): deepsea-ci-2.oa.suse.de
2017-07-20 16:46:30,165 1512 mod_wsgi ERROR exception#custom_handler - Internal Server Error: None
Traceback (most recent call last):
  File "/usr/lib/python2.7/site-packages/rest_framework/views.py", line 400, in dispatch
    response = handler(request, *args, **kwargs)
  File "/usr/lib/python2.7/site-packages/rest_framework/mixins.py", line 54, in create
    self.object = serializer.save(force_insert=True)
  File "/usr/lib/python2.7/site-packages/rest_framework/serializers.py", line 599, in save
    self.save_object(self.object, **kwargs)
  File "/usr/lib/python2.7/site-packages/rest_framework/serializers.py", line 1041, in save_object
    obj.save(**kwargs)
  File "/usr/share/openattic/ceph/models.py", line 842, in save
    stripe_unit=self.stripe_unit, stripe_count=self.stripe_count)
  File "/usr/share/openattic/nodb/models.py", line 316, in __get__
    self.eval_func(instance, query_set, self.field_names)
  File "/usr/share/openattic/ceph/models.py", line 811, in set_stripe_info
    if 'stripingv2' in self.features:
TypeError: argument of type 'NoneType' is not iterable
2017-07-20 16:49:42,971 1512 mod_wsgi WARNING ceph.models#save - Tried to set features, but they should already match. ['deep-flatten', 'exclusive-lock', 'layering', 'fast-diff', 'object-map'] != [u'deep-flatten', u'layering', u'exclusive-lock', u'object-map', u'fast-diff']