[gnome-mahjongg/arnaudb/wip/gtk4: 20/30] Adapt to HeaderBar API.

[Arnaud B. <arnaudb src gnome org>]

commit 5d2fe4601bd62f262a47656d8e3dd39b63abd0c0
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 a3531b8..5d0c4ba 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);