[gnome-mahjongg/arnaudb/wip/gtk4: 12/18] Adapt to HeaderBar API.

[Arnaud B. <arnaudb src gnome org>]

commit a8c324b2d8a16c0a9410738867d86b5a1fd40af9
Author: Arnaud Bonatti <arnaud bonatti gmail com>
Date:   Fri Mar 27 19:05:36 2020 +0100

    Adapt to HeaderBar API.

 src/gnome-mahjongg.vala | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
---
diff --git a/src/gnome-mahjongg.vala b/src/gnome-mahjongg.vala
index 569dda7..dc4e4f0 100644
--- a/src/gnome-mahjongg.vala
+++ b/src/gnome-mahjongg.vala
@@ -159,7 +159,7 @@ public class Mahjongg : Gtk.Application
 
         var header_bar = new Gtk.HeaderBar ();
         header_bar.set_custom_title (title_box);
-        header_bar.set_show_close_button (true);
+        header_bar.set_show_title_buttons (true);
         header_bar.pack_start (hbox);
         header_bar.pack_end (menu_button);
         header_bar.pack_end (hint_button);