[NbtkGtkLightSwitch] Use conventional translation marking notation
[NbtkGtkLightSwitch] Use conventional translation marking notation

jonnylamb/mx,jonnylamb/mx,clutter-project/mx,jonnylamb/mx,pwithnall/mx,pwithnall/mx,pwithnall/mx,clutter-project/mx,pwithnall/mx,jonnylamb/mx,clutter-project/mx,clutter-project/mx