Fix pep8 fail that crept in

Not sure how, but this crept in via https://review.openstack.org/#/c/281691/

Change-Id: I919276ee5204277dbc5e96f4de4b98381142423a

openstackclient/network/v2/router.py

@@ -339,4 +339,4 @@ class ShowRouter(command.ShowOne):
         obj = client.find_router(parsed_args.router, ignore_missing=False)
         columns = _get_columns(obj)
         data = utils.get_item_properties(obj, columns, formatters=_formatters)
-        return columns, data
+        return columns, data