added depext, for gegl on fedora

Author: fccm2

packages/conf-gegl/conf-gegl.1/opam

@@ -16,6 +16,7 @@ depexts: [
   ["gegl"] {os-distribution = "arch"}
   ["gegl"] {os = "freebsd"}
   ["gegl"] {os = "openbsd"}
+  ["gegl04-devel"] {os-family = "fedora"}
 ]
 build: [
   ["sh" "-c" "pkg-config --exists gegl-0.4"]