[Breeze window decoration] Use intersects instead of contains

Otherwise breaks if the entire deco is painted at once (e.g. window decoration KCM)

kdecoration/breezedecoration.cpp

@@ -476,7 +476,7 @@ namespace Breeze
         const auto c = client().data();
         const QRect titleRect(QPoint(0, 0), QSize(size().width(), borderTop()));
 
-        if ( !titleRect.contains(repaintRegion) ) return;
+        if ( !titleRect.intersects(repaintRegion) ) return;
 
         painter->save();
         painter->setPen(Qt::NoPen);