Client subscribing in on_connect,but messages sent on config not received  #2033

def on_connect(unused_client, unused_userdata, unused_flags, rc):
	"""Callback for when a device connects."""
	device_id=unused_userdata
	print('on_connect', error_str(rc))
	mqtt_config_topic = '/devices/{}/config'.format(args.device_id)
	print('Subscribing to {}'.format(mqtt_config_topic))
	client.subscribe(mqtt_config_topic, qos=1)

def main():
	global minimum_backoff_time
	args = parse_command_line_args()
	run_get(args)
	# Create our MQTT client. The client_id is a unique string that identifies
	# this device. For Google Cloud IoT Core, it must be in the format below.
	client = mqtt.Client(client_id=(	'projects/{}/locations/{}/registries/{}/devices/{}'
					.format(args.project_id, args.cloud_region,args.registry_id, args.device_id)), 
                                        clean_session=False)

	# With Google Cloud IoT Core, the username field is ignored, and the
	# password field is used to transmit a JWT to authorize the device.
	client.username_pw_set(
			username='unused',
			password=create_jwt(
					args.project_id, args.private_key_file, args.algorithm))

	# Enable SSL/TLS support.
	client.tls_set(ca_certs=args.ca_certs, tls_version=ssl.PROTOCOL_TLSv1_2)

	client.on_connect = on_connect
	client.on_publish = on_publish
	client.on_message=on_message
	client.on_disconnect = on_disconnect

	client.user_data_set(args.device_id)

	client.connect(args.mqtt_bridge_hostname, args.mqtt_bridge_port)
	time.sleep(5)
        client.loop_forever()