adding allow-none to pango_context_get_metrics parameters
adding allow-none to pango_context_get_metrics parameters

Distrotech/pango,kari-lentz/alpha-pango,danny-ku/pango,Distrotech/pango,kari-lentz/alpha-pango,danny-ku/pango,Distrotech/pango,kari-lentz/alpha-pango,kari-lentz/alpha-pango,danny-ku/pango