Revert "QTBUG-15319: fix shortcuts with secondary Xkb layout."

The change which attempted to fix QTBUG-15319 broke keyboard
shortcuts for non latin keyboard layouts.

This patch reverts QTBUG-15319 (f45cdeda8) since it caused a
regression.

Task-number: QTBUG-32908

Change-Id: I47d7984fa7986d5218d1f3ff1fc36d2ec67c9ba7
Reviewed-by: David Faure <david.faure@kdab.com>