Build fix for the screenshotcropper tool.

Change-Id: I440006e7fb409c1dc8c2ec111139bc8e0d499b03
Reviewed-by: Erik Verbruggen <erik.verbruggen@nokia.com>

src/tools/screenshotcropper/main.cpp

@@ -30,7 +30,10 @@
 **
 **************************************************************************/
 
-#include <QtWidgets>
+#include <QApplication>
+#include <QFileDialog>
+#include <QSettings>
+
 #include "screenshotcropperwindow.h"
 
 using namespace QtSupport::Internal;