Debugger: Log connection failures to QML/JS console

The debugger log is not very accessible and people may want to see this
message.

Change-Id: Id5e5a6d84f3576df3756d1fabc9f5801dcebac6e
Reviewed-by: hjk <hjk@theqtcompany.com>

src/plugins/debugger/qml/qmlengine.cpp

@@ -442,7 +442,7 @@ void QmlEngine::appStartupFailed(const QString &errorMessage)
                 this, &QmlEngine::errorMessageBoxFinished);
         infoBox->show();
     } else {
-        showMessage(error, StatusBar);
+        ConsoleManagerInterface::instance()->printToConsolePane(ConsoleItem::WarningType, error);
     }
 
     notifyEngineRunFailed();