D9334: Remove cmake 3.10+ warning for users of K_PLUGIN_FACTORY and K_PLUGIN_FACTORY_WITH_JSON

[Nathaniel Graham]

ngraham added a comment.


  We have a report in the wild that this broke compiling KWin with CMake 3.10.x 
for someone on Gentoo: https://bugs.kde.org/show_bug.cgi?id=387983

REPOSITORY
  R244 KCoreAddons

REVISION DETAIL
  https://phabricator.kde.org/D9334

To: mlaurent, dfaure
Cc: ngraham, #frameworks