[libgit2-glib] ggit-blob.c: Fix return annotations

[Igor Gnatenko <ignatenko src gnome org>]

commit 9e61a49f8da148f4834bca35e429f68236c992b6
Author: Brian C. Lane <bcl redhat com>
Date:   Wed Aug 30 15:36:42 2017 -0700

    ggit-blob.c: Fix return annotations
    
    Add (nullable) as needed.

 libgit2-glib/ggit-blob.c |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)
---
diff --git a/libgit2-glib/ggit-blob.c b/libgit2-glib/ggit-blob.c
index 2786184..b895530 100644
--- a/libgit2-glib/ggit-blob.c
+++ b/libgit2-glib/ggit-blob.c
@@ -74,7 +74,7 @@ _ggit_blob_wrap (git_blob *blob,
  * not be free'd. The pointer may be invalidated at a later
  * time.
  *
- * Returns: (array length=length) (element-type guchar): the blob content or
+ * Returns: (array length=length) (element-type guchar) (nullable): the blob content or
  *          %NULL if the blob does not have any content.
  *
  **/