terminal: Don't try to render RLE used as a placeholder
terminal: Don't try to render RLE used as a placeholder

weston-terminal uses RLE (U+202B) as a placeholder of the right half
of a double width character.  However, not all fonts include this
glyph and cairo renders it as .notdef (glyph index 0) in that case.

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