iot: update misnamed function in gateway_demo (GoogleCloudPlatform#1967)

hongalex · gguuss · commit fd7944ad50d3 · 2019-01-10T16:11:02.000-08:00
Mike found out that `gateway_demo.py` was still using the old function name `listen_for_config_messages` instead of `listen_for_config_and_error_messages`
diff --git a/iot/api-client/beta-features/gateway/gateway_demo.py b/iot/api-client/beta-features/gateway/gateway_demo.py
@@ -216,7 +216,7 @@ def log_on_message(unused_client, unused_userdata, message):
 
         client.on_message = log_on_message
 
-    gateway.listen_for_config_messages(
+    gateway.listen_for_config_and_error_messages(
                 service_account_json, project_id, cloud_region, registry_id,
                 device_id, gateway_id, num_messages, rsa_private_path, 'RS256',
                 ca_cert_path, mqtt_bridge_hostname, mqtt_bridge_port,
