Fix Look and Feel KCM Service Type
42d07438 adds incorrect ServiceType
for Look and Feel KCM .desktop file. I'm not sure about the purpose of the new one but it seems it overrides KCModule
type causing Global Theme KCM not to show in System Settings app. This MR removes Plasma/Generic
type.
Maybe both should present, I don't know exactly. In this case I'll correct my MR.