Qt::WFlags is obsolete in Qt5. Replace it with Qt::WindowFlags.

This change is Qt4/Qt5 neutral.

src/Gui/DlgRunExternal.cpp

@@ -46,7 +46,7 @@ using namespace Gui::Dialog;
  *  The dialog will by default be modeless, unless you set 'modal' to
  *  TRUE to construct a modal dialog.
  */
-DlgRunExternal::DlgRunExternal( QWidget* parent, Qt::WFlags fl )
+DlgRunExternal::DlgRunExternal( QWidget* parent, Qt::WindowFlags fl )
     : QDialog(parent, fl),process(this),advancedHidden(true)
 {
     ui = new Ui_DlgRunExternal();