UPnpNotifyTask::SendNotifyMsg(): remove QMutexLocker

This has not locked for the address list since 2008 with
0a3cbf5.

The only change is that UPnpNotifyTask::m_eNTS may now change, which is only
read to determine if the datagram should be sent twice.

mythtv/libs/libmythupnp/upnptasknotify.cpp

@@ -81,8 +81,6 @@ void UPnpNotifyTask::SendNotifyMsg( MSocketDevice *pSocket,
             .arg(pSocket->address().toString(), QString::number(pSocket->port()),
                  sNT, sUSN));
 
-    QMutexLocker qml(&m_mutex); // for addressList
-
     // -------------------------------------------------------------------
     // Refresh IP Address List in case of changes
     // -------------------------------------------------------------------