consume message from channel on the consuming thread.

def run(self):
        """
        consume message from channel on the consuming thread.
        """
        LOGGER.debug("zeromq.Subscriber.run")
        self.running = True
        self.is_started = True
        while self.running:
            msg = None
            try:
                msg = self.zmqsocket.recv_string(zmq.NOBLOCK)
            except zmq.ZMQError:
                time.sleep(0.1)
            except Exception as e:
                LOGGER.warn("zeromq.Subscriber.run - Exception raised while consuming on topic " + str(self.zmqtopic))
            if msg is not None:
                try:
                    self.cb(msg)
                except Exception as e:
                    LOGGER.warn("zeromq.Subscriber.run - Exception raised while treating msg {" + str(msg) + "}")
        self.is_started = False