configure.ac: add check for sigsetjmp(), it was forgotten when splitting the libs
configure.ac: add check for sigsetjmp(), it was forgotten when splitting the libs

djdeath/gdk-pixbuf,GNOME/gdk-pixbuf,YueLinHo/MB3Gdk-pixbuf,GNOME/gdk-pixbuf,GNOME/gdk-pixbuf,djdeath/gdk-pixbuf,Distrotech/gdk-pixbuf,djdeath/gdk-pixbuf,YueLinHo/MB3Gdk-pixbuf,Distrotech/gdk-pixbuf,Distrotech/gdk-pixbuf,YueLinHo/MB3Gdk-pixbuf,YueLinHo/MB3Gdk-pixbuf,Distrotech/gdk-pixbuf,djdeath/gdk-pixbuf,Distrotech/gdk-pixbuf,YueLinHo/MB3Gdk-pixbuf,GNOME/gdk-pixbuf