D6558: do not stderr that NoDisplay is set

[David Faure]

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

REPOSITORY
  R290 KPackage

BRANCH
  master

REVISION DETAIL
  https://phabricator.kde.org/D6558

To: sitter, mart, sebas, apol, dfaure
Cc: #frameworks