Add a window title for the QPrintDialog Properties dialog

Change-Id: Ia74edf45e78fb81256da86d572459b3ed38663d4
Reviewed-by: Friedemann Kleint <Friedemann.Kleint@theqtcompany.com>

src/printsupport/dialogs/qprintdialog_unix.cpp

@@ -231,6 +231,7 @@ public:
 QPrintPropertiesDialog::QPrintPropertiesDialog(QAbstractPrintDialog *parent)
     : QDialog(parent)
 {
+    setWindowTitle(tr("Printer Properties"));
     QVBoxLayout *lay = new QVBoxLayout(this);
     this->setLayout(lay);
     QWidget *content = new QWidget(this);