[gnome-nibbles/arnaudb/wip/gtk4: 28/40] Small fix.

[Arnaud B. <arnaudb src gnome org>]

commit a8b73ce8bf5582081915b4c729b12fcda5aae724
Author: Arnaud Bonatti <arnaud bonatti gmail com>
Date:   Tue Jun 16 11:22:25 2020 +0200

    Small fix.

 src/controls.vala | 3 +++
 1 file changed, 3 insertions(+)
---
diff --git a/src/controls.vala b/src/controls.vala
index 51a9d3a..c01b354 100644
--- a/src/controls.vala
+++ b/src/controls.vala
@@ -38,7 +38,10 @@ private class Controls : Box
     {
         Widget? widget;
         while ((widget = grids_box.get_first_child ()) != null)
+        {
+            widget.unparent ();
             widget.destroy ();
+        }
 
         GenericSet<uint> duplicate_keys     = new GenericSet<uint> (direct_hash, direct_equal);
         GenericSet<uint> encountered_keys   = new GenericSet<uint> (direct_hash, direct_equal);