[gnome-chess/arnaudb/wip/gtk4: 20/31] Adapt to InfoBar API.

[Arnaud B. <arnaudb src gnome org>]

commit a01b7b9d4b63442b00111156ba023ca679d5f5b2
Author: Arnaud Bonatti <arnaud bonatti gmail com>
Date:   Tue Apr 7 10:23:05 2020 +0200

    Adapt to InfoBar API.

 src/gnome-chess.vala | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
---
diff --git a/src/gnome-chess.vala b/src/gnome-chess.vala
index c3cceca..ff02326 100644
--- a/src/gnome-chess.vala
+++ b/src/gnome-chess.vala
@@ -137,7 +137,7 @@ Copyright © 2015–2016 Sahil Sareen""";
         label.set_wrap (true);
         label.show ();
 
-        info_bar.get_content_area ().add (label);
+        info_bar.add (label);
         info_bar.set_message_type (MessageType.ERROR);
         info_bar.set_show_close_button (true);
         info_bar.response.connect (() => info_bar.destroy ());