[five-or-more/ricotz/vala] Reference of [GtkChild] fields is handled by GtkBuilder, type must be unowned

[Rico Tzschichholz <ricotz src gnome org>]

commit d38a281cfbf028879ac15b11081609b59a140068
Author: Rico Tzschichholz <ricotz ubuntu com>
Date:   Wed Mar 17 11:14:13 2021 +0100

    Reference of [GtkChild] fields is handled by GtkBuilder, type must be unowned

 src/window.vala | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)
---
diff --git a/src/window.vala b/src/window.vala
index 9f6e048..4351f6a 100644
--- a/src/window.vala
+++ b/src/window.vala
@@ -27,13 +27,13 @@ using Gtk;
 private class GameWindow : ApplicationWindow
 {
     [GtkChild]
-    private HeaderBar headerbar;
+    private unowned HeaderBar headerbar;
 
     [GtkChild]
-    private Box preview_hbox;
+    private unowned Box preview_hbox;
 
     [GtkChild]
-    private Games.GridFrame grid_frame;
+    private unowned Games.GridFrame grid_frame;
 
     private GLib.Settings settings = new GLib.Settings ("org.gnome.five-or-more");
     private bool window_tiled;