D15872: Fix Oxygen background gradient for QML modules

[Filip Fila]

filipf added a reviewer: Plasma.

REPOSITORY
  R295 KCMUtils

REVISION DETAIL
  https://phabricator.kde.org/D15872

To: hwti, mart, #vdg, #plasma
Cc: filipf, kde-frameworks-devel, michaelh, ngraham, bruns