D6571: Delete all Wayland connections by plugins prior to own Wayland connection

[David Edmundson]

davidedmundson accepted this revision.

REPOSITORY
  R108 KWin

BRANCH
  connection-cleanup

REVISION DETAIL
  https://phabricator.kde.org/D6571

To: graesslin, #kwin, #plasma, mart, davidedmundson
Cc: davidedmundson, plasma-devel, kwin, ZrenBot, progwolff, lesliezhai, 
ali-mohamed, jensreuterberg, abetts, sebas, apol, mart, lukas