[NbtkLightSwitch] remove unicode characters from comments
[NbtkLightSwitch] remove unicode characters from comments

This caused problems with xgettext

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