D22979: Security: remove support for $(...) in config keys with [$e] marker.

[Albert Astals Cid]

aacid added a reviewer: security-team.

REPOSITORY
  R237 KConfig

REVISION DETAIL
  https://phabricator.kde.org/D22979

To: dfaure, mdawson, aacid, broulik, davidedmundson, kossebau, apol, sitter, 
security-team
Cc: ngraham, kde-frameworks-devel, LeGast00n, michaelh, bruns