Fix DBus service used in shutdown interface
During Plasma 5.18, ksmserver was split so it hosted the new new shutdown interface registering both services names org.kde.ksmserver and org.kde.Shutdown.
This way we could do a gradual port, update the libs now, and migrate the final code without any breakages. At least that was the theory.
In 5.19 we did the final actual splitting, unfortunately in libkworkspace the path where we skip logout confirmation had the wrong name.