weston-launcher: Add missing newline in error message
weston-launcher: Add missing newline in error message

mchalupa/weston,Gnurou/weston,udoprog/weston,Tarnyko/weston-xdg_surface_present,Gnurou/weston,xorgy/weston,Fantu/compositor-spice,Tarnyko/weston-xdg_surface_present,Fantu/compositor-spice,kwm81/weston,eyolfson/weston,jonnylamb/weston,krezovic/weston,eyolfson/weston,sir-murray/weston,kwm81/weston,jonnylamb/weston,krezovic/weston,xorgy/weston,Fantu/compositor-spice,udoprog/weston,sir-murray/weston,giucam/weston,mchalupa/weston,giucam/weston