[gnome-shell] Add missing allow-none for st_bin_set_child

[Colin Walters <walters src gnome org>]

commit b8d9319c3269b2725de411403c3ef59c95a47f7b
Author: Colin Walters <walters verbum org>
Date:   Fri Oct 23 15:14:41 2009 -0400

    Add missing allow-none for st_bin_set_child
    
    https://bugzilla.gnome.org/show_bug.cgi?id=599442

 src/st/st-bin.c |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)
---
diff --git a/src/st/st-bin.c b/src/st/st-bin.c
index 4c862b6..48347b6 100644
--- a/src/st/st-bin.c
+++ b/src/st/st-bin.c
@@ -545,7 +545,7 @@ st_bin_new (void)
 /**
  * st_bin_set_child:
  * @bin: a #StBin
- * @child: a #ClutterActor, or %NULL
+ * @child: (allow-none): a #ClutterActor, or %NULL
  *
  * Sets @child as the child of @bin.
  *