Cleanup and gate on hacking E713 rule

This fixes the offending instances of the rule
and removes it from the ignore list in tox.ini
so that we can gate on the E713 rule.

Change-Id: I1f9ef23a8569252b5b6fa660d0d200b1702056d0

nova/api/openstack/compute/servers.py

@@ -1266,7 +1266,7 @@ class Controller(wsgi.Controller):
     @wsgi.action('changePassword')
     def _action_change_password(self, req, id, body):
         context = req.environ['nova.context']
-        if (not 'changePassword' in body
+        if ('changePassword' not in body
                 or 'adminPass' not in body['changePassword']):
             msg = _("No adminPass was specified")
             raise exc.HTTPBadRequest(explanation=msg)