Don't clear hover state while a child dialog is open.

Otherwise it won't stay open.

Fixes regression from 7585f295363532eff51f7e11ef6b62925117aba4.

The bug number referenced in the original change is invalid, but
I don't think this should invalidate the intent of that fix. Kai
please let me know the correct bug number so I can double-check.

BUG:374291
CCMAIL:kde@privat.broulik.de