[gtk/wip/baedert/for-master] Add nullable annotations to GtkShortcutFunc

[Timm Bäder <baedert src gnome org>]

commit a3949763f2a5bb77f7cd64e07b4d5d9f88f70e6c
Author: Timm Bäder <mail baedert org>
Date:   Sun Jan 17 08:11:42 2021 +0100

    Add nullable annotations to GtkShortcutFunc
    
    Fixes #3593

 gtk/gtkshortcutaction.h | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)
---
diff --git a/gtk/gtkshortcutaction.h b/gtk/gtkshortcutaction.h
index 9c874a641b..9c15172a96 100644
--- a/gtk/gtkshortcutaction.h
+++ b/gtk/gtkshortcutaction.h
@@ -33,8 +33,8 @@ G_BEGIN_DECLS
 /**
  * GtkShortcutFunc:
  * @widget: The widget passed to the activation
- * @args: The arguments passed to the activation
- * @user_data: The user data provided when activating the action
+ * @args: (nullable): The arguments passed to the activation
+ * @user_data: (nullable): The user data provided when activating the action
  *
  * Prototype for shortcuts based on user callbacks.
  */