Moved extra test on useFlatBackground from renderWindowBackground to renderHoleBackground, because of false positives triggered in the former implementation.
Moved extra test on useFlatBackground from renderWindowBackground to renderHoleBackground, because of false positives triggered in the former
implementation.

KDE/oxygen-gtk,KDE/oxygen-gtk,blueshell-next/carbon-gtk,blue-shell/carbon-gtk,blue-shell/carbon-gtk,blueshell-next/carbon-gtk