[gtk/bilelmoussaoui/g-i] g-i: mark gtk_text_iter_get_child_anchor as nullable

[Bilal Elmoussaoui <bilelmoussaoui src gnome org>]

commit ffa93b87f826e7a54c46c0563767d146ddd595ce
Author: Bilal Elmoussaoui <bil elmoussaoui gmail com>
Date:   Wed Jan 19 10:18:40 2022 +0000

    g-i: mark gtk_text_iter_get_child_anchor as nullable

 gtk/gtktextiter.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
---
diff --git a/gtk/gtktextiter.c b/gtk/gtktextiter.c
index fd96ca6b72..d3a094826f 100644
--- a/gtk/gtktextiter.c
+++ b/gtk/gtktextiter.c
@@ -1056,7 +1056,7 @@ gtk_text_iter_get_paintable (const GtkTextIter *iter)
  *
  * Otherwise, %NULL is returned.
  *
- * Returns: (transfer none): the anchor at @iter
+ * Returns: (transfer none) (nullable): the anchor at @iter
  **/
 GtkTextChildAnchor*
 gtk_text_iter_get_child_anchor (const GtkTextIter *iter)