D17558: Fix XDGForeign Client header installs

[Vlad Zagorodniy]

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

REPOSITORY
  R127 KWayland

BRANCH
  master

REVISION DETAIL
  https://phabricator.kde.org/D17558

To: davidedmundson, zzag
Cc: kde-frameworks-devel, michaelh, ngraham, bruns