[gtk+] Expander: Annotate new()’s label arg as nullable

[Daniel Boles <dboles src gnome org>]

commit 89790bb41223273d76e16570abe5564065ab2b6d
Author: Daniel Boles <dboles src gnome org>
Date:   Thu Sep 14 21:19:33 2017 +0100

    Expander: Annotate new()’s label arg as nullable
    
    to match new_with_mnemonic()

 gtk/gtkexpander.c |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)
---
diff --git a/gtk/gtkexpander.c b/gtk/gtkexpander.c
index 8fc88d4..6e9b430 100644
--- a/gtk/gtkexpander.c
+++ b/gtk/gtkexpander.c
@@ -957,7 +957,7 @@ gtk_expander_measure (GtkWidget      *widget,
 
 /**
  * gtk_expander_new:
- * @label: the text of the label
+ * @label: (nullable): the text of the label
  *
  * Creates a new expander using @label as the text of the label.
  *