[gnome-sudoku] Make winning message dialog modal

[Michael Catanzaro <mcatanzaro src gnome org>]

commit e1f5d90b652e9d8ca5f972d34fdce57f6c3e6703
Author: Andrey Kutejko <andy128k gmail com>
Date:   Wed Dec 23 02:44:30 2020 +0100

    Make winning message dialog modal

 src/gnome-sudoku.vala | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
---
diff --git a/src/gnome-sudoku.vala b/src/gnome-sudoku.vala
index 1bad01c8..51a77ca3 100644
--- a/src/gnome-sudoku.vala
+++ b/src/gnome-sudoku.vala
@@ -452,7 +452,7 @@ public class Sudoku : Gtk.Application
             var time_str = ngettext ("Well done, you completed the puzzle in %d minute!",
                                      "Well done, you completed the puzzle in %d minutes!",
                                      minutes).printf (minutes);
-            var dialog = new MessageDialog (window, DialogFlags.DESTROY_WITH_PARENT, MessageType.INFO, 
ButtonsType.NONE, time_str);
+            var dialog = new MessageDialog (window, DialogFlags.MODAL, MessageType.INFO, ButtonsType.NONE, 
time_str);
 
             dialog.add_button (_("_Quit"),       ResponseType.REJECT);
             dialog.add_button (_("Play _Again"), ResponseType.ACCEPT);