Wait a bit longer for portfwd thread to exit to avoid crashes on exit

src/libtomahawk/network/portfwdthread.cpp

@@ -43,7 +43,7 @@ PortFwdThread::~PortFwdThread()
 {
     qDebug() << Q_FUNC_INFO << "waiting for event loop to finish...";
     quit();
-    wait( 1000 );
+    wait( 6000 );
 
     delete m_portfwd;
 }