Open or restricted group admin page crashes when group has no organization

[sentry-io[bot]]

Sentry Issue: H-2TB

AttributeError: 'NoneType' object has no attribute 'pubid'
(18 additional frame(s) were not displayed)
...
  File "h/tweens.py", line 139, in rollback_db_session_on_exception
    return handler(request)
  File "h/tweens.py", line 20, in conditional_http_tween
    response = handler(request)
  File "h/viewderivers.py", line 30, in wrapper_view
    resp = view(context, request)
  File "h/views/admin/groups.py", line 156, in read
    self._update_appstruct()
  File "h/views/admin/groups.py", line 220, in _update_appstruct
    "organization": group.organization.pubid,