[pygtksourceview] set_mark_category_icon_from_stock should accept None for stock

[Gian Mario Tagliaretti <gianmt src gnome org>]

commit d21ad00457d30c9a8046658b4e8d60d9c845e184
Author: Gian Mario Tagliaretti <gianmt gnome org>
Date:   Mon Aug 17 20:57:05 2009 +0200

    set_mark_category_icon_from_stock should accept None for stock

 gtksourceview2.defs |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)
---
diff --git a/gtksourceview2.defs b/gtksourceview2.defs
index 13ed2d4..7e501cd 100644
--- a/gtksourceview2.defs
+++ b/gtksourceview2.defs
@@ -918,7 +918,7 @@
   (return-type "none")
   (parameters
     '("const-gchar*" "category")
-    '("const-gchar*" "stock_id")
+    '("const-gchar*" "stock_id" (null-ok))
   )
 )