[gnome-chess] Update header bar title after Undo

[Michael Catanzaro <mcatanzaro src gnome org>]

commit e75dc1ceea1d676ed6770b9168881efc1ef59c2b
Author: Michael Catanzaro <mcatanzaro gnome org>
Date:   Sun Mar 23 23:40:49 2014 -0500

    Update header bar title after Undo
    
    Now that we display the name of the player to move, we need to remember
    to keep this updated even if we go back in time.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=726950

 src/gnome-chess.vala |    2 ++
 1 files changed, 2 insertions(+), 0 deletions(-)
---
diff --git a/src/gnome-chess.vala b/src/gnome-chess.vala
index 2a15d76..cfae17e 100644
--- a/src/gnome-chess.vala
+++ b/src/gnome-chess.vala
@@ -1375,6 +1375,8 @@ public class Application : Gtk.Application
             human_player.undo ();
         else
             game.opponent.undo ();
+
+        update_headerbar_title ();
     }
 
     public void pause_resume_cb ()