[gnome-chess] view: properly disconnect scene_changed_cb

[Michael Catanzaro <mcatanzaro src gnome org>]

commit 574158dbb9d6ee1f32487c83be351348783bcbf3
Author: Michael Catanzaro <mcatanzaro gnome org>
Date:   Thu Dec 24 17:58:07 2020 -0600

    view: properly disconnect scene_changed_cb

 src/chess-view.vala | 1 +
 1 file changed, 1 insertion(+)
---
diff --git a/src/chess-view.vala b/src/chess-view.vala
index ed854d5..72268e5 100644
--- a/src/chess-view.vala
+++ b/src/chess-view.vala
@@ -27,6 +27,7 @@ public class ChessView : Gtk.DrawingArea
         get { return _scene; }
         set
         {
+            _scene.changed.disconnect (scene_changed_cb);
             _scene = value;
             _scene.changed.connect (scene_changed_cb);
             queue_draw ();