[gnome-nibbles/arnaudb/wip/gtk4] Fix Scoreboard.

[Arnaud B. <arnaudb src gnome org>]

commit 7c4a175df9f77d16f40fee6d3b20d181cf8c3a25
Author: Arnaud Bonatti <arnaud bonatti gmail com>
Date:   Wed Jun 17 18:09:20 2020 +0200

    Fix Scoreboard.

 src/scoreboard.vala | 1 +
 1 file changed, 1 insertion(+)
---
diff --git a/src/scoreboard.vala b/src/scoreboard.vala
index e6bc780..0b883e7 100644
--- a/src/scoreboard.vala
+++ b/src/scoreboard.vala
@@ -50,6 +50,7 @@ private class Scoreboard : Box
         foreach (var entry in boxes.entries)
         {
             var box = entry.key;
+            box.unparent ();
             box.destroy ();
         }
         boxes.clear ();