PrintCompositor: fix syntax highlighting
PrintCompositor: fix syntax highlighting

GdkRGBA has values between 0 and 1, and pango wants values between 0 and
65535 (like GdkColor).

https://bugzilla.gnome.org/show_bug.cgi?id=728180

GNOME/gtksourceview,cburschka/gtksourceview,GNOME/gtksourceview,cburschka/gtksourceview,GNOME/gtksourceview,uajain/gtksourceview,cburschka/gtksourceview,uajain/gtksourceview,uajain/gtksourceview,cburschka/gtksourceview,uajain/gtksourceview,GNOME/gtksourceview,GNOME/gtksourceview,uajain/gtksourceview,GNOME/gtksourceview,uajain/gtksourceview,GNOME/gtksourceview,GNOME/gtksourceview,GNOME/gtksourceview,cburschka/gtksourceview,GNOME/gtksourceview,cburschka/gtksourceview,GNOME/gtksourceview,cburschka/gtksourceview,cburschka/gtksourceview,cburschka/gtksourceview,uajain/gtksourceview,cburschka/gtksourceview,GNOME/gtksourceview,uajain/gtksourceview,GNOME/gtksourceview,uajain/gtksourceview,GNOME/gtksourceview,GNOME/gtksourceview,uajain/gtksourceview