[gnome-applets/wip/muktupavels/werror] sticky-notes: fix -Wswitch-default warning

[Alberts Muktupāvels <muktupavels src gnome org>]

commit 6e25f228d49e7df47a3a25eb16af3facd15450b1
Author: Alberts Muktupāvels <alberts muktupavels gmail com>
Date:   Sat Apr 4 22:18:46 2020 +0300

    sticky-notes: fix -Wswitch-default warning

 gnome-applets/sticky-notes/sticky-notes-applet-callbacks.c | 3 +++
 1 file changed, 3 insertions(+)
---
diff --git a/gnome-applets/sticky-notes/sticky-notes-applet-callbacks.c 
b/gnome-applets/sticky-notes/sticky-notes-applet-callbacks.c
index 8920fff2f..91bbd092f 100644
--- a/gnome-applets/sticky-notes/sticky-notes-applet-callbacks.c
+++ b/gnome-applets/sticky-notes/sticky-notes-applet-callbacks.c
@@ -120,6 +120,9 @@ applet_key_cb (GtkWidget         *widget,
                case GDK_KEY_Return:
                        stickynote_show_notes (TRUE);
                        return TRUE;
+
+               default:
+                       break;
        }
        return FALSE;
 }