Qt::WFlags is obsolete in Qt5.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

This change is Qt4/Qt5 neutral.

src/Gui/DlgMaterialPropertiesImp.cpp

@@ -43,7 +43,7 @@ using namespace Gui::Dialog;
  *  The dialog will by default be modeless, unless you set 'modal' to
  *  TRUE to construct a modal dialog.
  */
-DlgMaterialPropertiesImp::DlgMaterialPropertiesImp(const std::string& mat, QWidget* parent, Qt::WFlags fl)
+DlgMaterialPropertiesImp::DlgMaterialPropertiesImp(const std::string& mat, QWidget* parent, Qt::WindowFlags fl)
   : QDialog(parent, fl), material(mat)
 {
     this->setupUi(this);