gdk-pixbuf: fix build dependencies

package/gdk-pixbuf/Makefile

@@ -10,7 +10,7 @@ PKG_RELEASE:=		1
 PKG_HASH:=		d55e5b383ee219bd0e23bf6ed4427d56a7db5379729a6e3e0a0e0eba9a8d8879
 PKG_DESCR:=		image loading and pixel buffer manipulation library
 PKG_SECTION:=		libs/image
-PKG_BUILDDEP:=		libjpeg-turbo libtiff
+PKG_BUILDDEP:=		libjpeg-turbo libtiff glib libpng
 HOST_BUILDDEP:=		glib-host libffi-host
 PKG_NEEDS:=		c++
 PKG_SITES:=		$(MASTER_SITE_GNOME:=gdk-pixbuf/$(PKG_EXTRAVER)/)