[pygtksourceview] set_mark_category_icon_from_pixbuf should accept None for pixbuf

[Gian Mario Tagliaretti <gianmt src gnome org>]

commit 9f657875f76e1a28441f2fe12c0df93b8614b4e7
Author: Gian Mario Tagliaretti <gianmt gnome org>
Date:   Mon Aug 17 20:56:16 2009 +0200

    set_mark_category_icon_from_pixbuf should accept None for pixbuf

 gtksourceview2.defs |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)
---
diff --git a/gtksourceview2.defs b/gtksourceview2.defs
index 6047e42..13ed2d4 100644
--- a/gtksourceview2.defs
+++ b/gtksourceview2.defs
@@ -908,7 +908,7 @@
   (return-type "none")
   (parameters
     '("const-gchar*" "category")
-    '("GdkPixbuf*" "pixbuf")
+    '("GdkPixbuf*" "pixbuf" (null-ok))
   )
 )