Fix montior tests to handle the monitor stopped event correctly

tests/test_monitor.cpp

@@ -58,7 +58,11 @@ static bool read_msg(void* s, zmq_event_t& event, std::string& ep)
     memcpy(&event.value, data+sizeof(event.event), sizeof(event.value));
     // copy address part
     ep = std::string((char*)zmq_msg_data(&msg2), zmq_msg_size(&msg2));
-    return false ;
+
+	if (event.event == ZMQ_EVENT_MONITOR_STOPPED)
+		return true;
+
+    return false;
 }