gdk-pixbuf2 needs librsvg run time dependency

[adr <adr%sdf.org@localhost>]

Hi,

without librsvg applications using pixbuf2 can't load svg icons.
Sometimes it is just missed icons, but applications can run with
problems.  Just add .include "../../graphics/librsvg/buildlink3.mk"
to graphics/gdk-pixbuf2/Makefile?

Sorry I haven't tested, I'm using binary packages in netbsd 10
right now.

Regards,
adr.