package/xscreensaver: add gdk-pixbuf-xlib dependency
gdk-pixbuf-xlib dependency is needed since bump of gdk-pixbuf to version
2.42.2 in commit a7b51ed3013c919b293deb95299e33363fb9df70 to avoid the
following "hidden" warnings:
Warning: GTK version 2.24.33 was found, but at least one supporting
library (gdk-pixbuf-xlib-2.0) was not, so GTK can't be used.
Perhaps some of the development packages are not installed?
Warning: The GTK libraries do not seem to be available; the
`xscreensaver-demo' program requires them.
Warning: The GDK-Pixbuf library was not found.
The PNG library is being used instead.
Some of the demos will not use images as much as they could.
You should consider installing GDK-Pixbuf and re-running
configure.
Signed-off-by: Fabrice Fontaine <fontaine.fabrice@gmail.com>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>