D10868: [4/5] Fix CheckBox script usage

[Albert Astals Cid]

aacid accepted this revision.
This revision is now accepted and ready to land.

REPOSITORY
  R223 Okular

REVISION DETAIL
  https://phabricator.kde.org/D10868

To: aheinecke, #okular, aacid
Cc: michaelweghorn, ngraham, aacid