D12014: [kcoreaddons] convert to new connect syntax

[David Faure]

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

REPOSITORY
  R244 KCoreAddons

REVISION DETAIL
  https://phabricator.kde.org/D12014

To: jtamate, dfaure
Cc: #frameworks, michaelh, ngraham, bruns