D6792: Make sure the dbus xml interface file exists before it's used

[David Edmundson]

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

REPOSITORY
  R101 KHotKeys

BRANCH
  Plasma/5.10

REVISION DETAIL
  https://phabricator.kde.org/D6792

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