[gegl] Revert accidental bump in required GDK Pixbuf version

[Jon Nordby <jonnor src gnome org>]

commit d07465c76b925158de85f818d3c4a483f719b8c1
Author: Jon Nordby <jononor gmail com>
Date:   Sun Jun 26 10:22:26 2011 +0200

    Revert accidental bump in required GDK Pixbuf version
    
    Change introduced in afb5da0d8602924d4256841095428b85c1d67bb2

 configure.ac |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)
---
diff --git a/configure.ac b/configure.ac
index 35de2eb..2f11ab1 100644
--- a/configure.ac
+++ b/configure.ac
@@ -39,7 +39,7 @@ m4_define([gimp_full_name], [Generic Graphical Library])
 # required versions of external libraries
 m4_define([babl_required_version], [0.1.4])
 m4_define([glib_required_version], [2.22.0])
-m4_define([gdk_pixbuf_required_version], [2.24])
+m4_define([gdk_pixbuf_required_version], [2.18.0])
 m4_define([lua_required_version], [5.1.0])
 m4_define([cairo_required_version], [0.0.0])
 m4_define([pango_required_version], [0.0.0])