encoding: fix leak of variant
encoding: fix leak of variant

g_variant_parse() returns a GVariant that does not have a floating
reference. Therefore, the ref_sink() was raising the reference count to
two instead of sinking the non-existent floating ref.

GNOME/gtksourceview,GNOME/gtksourceview,GNOME/gtksourceview,GNOME/gtksourceview,GNOME/gtksourceview,GNOME/gtksourceview,GNOME/gtksourceview,GNOME/gtksourceview,GNOME/gtksourceview,GNOME/gtksourceview,GNOME/gtksourceview,GNOME/gtksourceview,GNOME/gtksourceview,GNOME/gtksourceview,GNOME/gtksourceview