In windows Backtab key event always comes as "Shift+Backtab". So in order for Backtab key to be recognized as a shortcut sequence, we also consider Backtab without shift modifier a possibility. Fixes: QTBUG-94890 Change-Id: I20a7b404b57d8df5bea23765257a178f2e098ed0 Pick-to: 6.8 Reviewed-by: Oliver Wolff <oliver.wolff@qt.io>