[gnome-mahjongg/arnaudb/wip/gtk4: 22/24] Adapt to HeaderBar API.

[Arnaud B. <arnaudb src gnome org>]

commit 4d242f2b231e8e5919355c26464ce2fc28c3e395
Author: Arnaud Bonatti <arnaud bonatti gmail com>
Date:   Thu Aug 6 17:19:05 2020 +0200

    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 2aaa298..1aa8696 100644
--- a/src/gnome-mahjongg.vala
+++ b/src/gnome-mahjongg.vala
@@ -166,7 +166,7 @@ public class Mahjongg : Gtk.Application
         menu_button.set_icon_name ("open-menu-symbolic");
 
         var header_bar = new HeaderBar ();
-        header_bar.set_custom_title (title_box);
+        header_bar.set_title_widget (title_box);
         header_bar.set_show_title_buttons (true);
         header_bar.pack_start (hbox);
         header_bar.pack_end (menu_button);