Change update_subscription to change endpoint URL. [(#1344)](https://github.com/GoogleCloudPlatform/python-docs-samples/issues/1344)
Change update_subscription to change endpoint URL. [(#1344)](https://github.com/GoogleCloudPlatform/python-docs-samples/issues/1344)

The documentation specifies that the update subscription commands show how to update an endpoint URL: https://cloud.google.com/pubsub/docs/admin#update_a_subscription.
googleapis/python-pubsub,googleapis/python-pubsub