Merge pull request #4424 from mavlink/udp_multicast

UDP join multicast group for windows client

src/comm/UDPLink.cc

@@ -245,6 +245,7 @@ bool UDPLink::_hardwareConnect()
     _socket->setProxy(QNetworkProxy::NoProxy);
     _connectState = _socket->bind(host, _udpConfig->localPort(), QAbstractSocket::ReuseAddressHint | QUdpSocket::ShareAddress);
     if (_connectState) {
+        _socket->joinMulticastGroup(QHostAddress("224.0.0.1"));
         //-- Make sure we have a large enough IO buffers
 #ifdef __mobile__
         _socket->setSocketOption(QAbstractSocket::SendBufferSizeSocketOption,     64 * 1024);