qt: fix QDateTime warning when Qt 5.14 is used

Signed-off-by: Pierre Lamot <pierre@videolabs.io>

modules/gui/qt/dialogs/epg/EPGView.cpp

@@ -47,7 +47,12 @@ void EPGGraphicsScene::drawBackground( QPainter *painter, const QRectF &rect)
 
     /* day change */
     QDateTime rectstarttime = epgView->startTime().addSecs( rect.left() );
+#if QT_VERSION >= QT_VERSION_CHECK(5, 14, 0)
+    QDateTime nextdaylimit = rectstarttime.date().startOfDay();
+#else
     QDateTime nextdaylimit = QDateTime( rectstarttime.date() );
+#endif
+
     QRectF area( rect );
     while( area.left() < width() )
     {