[mutter] clutter/pick-stack: Add a copyright for Canonical

[Marge Bot <marge-bot src gnome org>]

commit e91062aaec7e67eca44d062a2e8f098b6c0ef148
Author: Daniel van Vugt <daniel van vugt canonical com>
Date:   Tue Dec 1 18:00:13 2020 +0800

    clutter/pick-stack: Add a copyright for Canonical
    
    Where much of the logic was introduced in commit 14c706e51b
    
    Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1619>

 clutter/clutter/clutter-pick-stack.c | 1 +
 1 file changed, 1 insertion(+)
---
diff --git a/clutter/clutter/clutter-pick-stack.c b/clutter/clutter/clutter-pick-stack.c
index 5a2260a8ea..2a18fa3d38 100644
--- a/clutter/clutter/clutter-pick-stack.c
+++ b/clutter/clutter/clutter-pick-stack.c
@@ -1,5 +1,6 @@
 /*
  * Copyright (C) 2020 Endless OS Foundation, LLC
+ * Copyright (C) 2018 Canonical Ltd.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Lesser General Public