stop requester

def on_stop(self):
        """
        stop requester
        """
        LOGGER.debug("rabbitmq.Requester.on_stop")
        try:
            self.channel.close()
        except Exception as e:
            LOGGER.warn("rabbitmq.Requester.on_stop - Exception raised while closing channel")
        try:
            self.connection.close()
        except Exception as e:
            LOGGER.warn("rabbitmq.Requester.on_stop - Exception raised while closing connection")