D20149: Fix compilation

[Albert Astals Cid]

aacid added subscribers: pino, apol, svuorela.

REPOSITORY
  R287 KImageFormats

REVISION DETAIL
  https://phabricator.kde.org/D20149

To: aacid
Cc: svuorela, apol, pino, kde-frameworks-devel, michaelh, ngraham, bruns