Debugger: Proactively try to connect to QML port in mixed engine

Just like with the QML-only engine we might not get the output for a
variety of reasons. As we've specified the port on the command line,
it's likely that the application will start listening at some point,
though.

Change-Id: Ifda69ba15c659cf95e708d35bed34cfb9b3c40ec
Task-number: QTCREATORBUG-15409
Reviewed-by: Christian Stenger <christian.stenger@theqtcompany.com>

src/plugins/debugger/qml/qmlengine.cpp

@@ -355,10 +355,8 @@ void QmlEngine::tryToConnect(quint16 port)
     if (state() == EngineRunRequested) {
         if (isSlaveEngine()) {
             // Probably cpp is being debugged and hence we did not get the output yet.
-            if (!masterEngine()->isDying()) {
-                d->noDebugOutputTimer.setInterval(4000);
-                d->noDebugOutputTimer.start();
-            }
+            if (!masterEngine()->isDying())
+                beginConnection(port);
             else
                 appStartupFailed(tr("No application output received in time"));
         } else {