[iagno] Back button removed when the game is launched

[Michael Catanzaro <mcatanzaro src gnome org>]

commit 62928ab1d9f1baad4636f04d16e80f7cc2ddf557
Author: amishas157 <amishas157 gmail com>
Date:   Fri Sep 26 18:33:54 2014 +0530

    Back button removed when the game is launched
    
    https://bugzilla.gnome.org/show_bug.cgi?id=664976

 src/iagno.vala |    5 ++---
 1 files changed, 2 insertions(+), 3 deletions(-)
---
diff --git a/src/iagno.vala b/src/iagno.vala
index 7e44df3..0a8c7ac 100644
--- a/src/iagno.vala
+++ b/src/iagno.vala
@@ -291,16 +291,15 @@ public class Iagno : Gtk.Application
             computer.cancel_move ();
 
         main_stack.set_visible_child_name ("start-box");
-        back_button.sensitive = game != null;
-        back_button.visible = true;
         undo_button.visible = false;
-        back_action.set_enabled (true);
     }
 
     private void new_game_cb ()
     {
         show_new_game_screen ();
         headerbar.set_subtitle (null);
+        back_button.visible = true;
+        back_action.set_enabled (true);
     }
 
     private void start_game ()