QmlObserver: Use new 4.7.1 API to enable qml debugging

Qml debugging is now disabled by default, and has to be enabled
explicitly (b2016bbfc9). This has to be done before the
QDView/QDEngine is instantiated ...

Reviewed-by: Alessandro Portale

share/qtcreator/qml/qmlobserver/main.cpp

@@ -50,6 +50,7 @@
 #include <QDebug>
 #include <QMessageBox>
 #include "qdeclarativetester.h"
+#include "private/qdeclarativedebughelper_p.h"
 
 QT_USE_NAMESPACE
 
@@ -361,6 +362,9 @@ int main(int argc, char ** argv)
     if (stayOnTop)
         wflags |= Qt::WindowStaysOnTopHint;
 
+    // enable remote debugging
+    QDeclarativeDebugHelper::enableDebugging();
+
     QDeclarativeViewer *viewer = new QDeclarativeViewer(0, wflags);
     viewer->setAttribute(Qt::WA_DeleteOnClose, true);
     if (!scriptopts.isEmpty()) {