[libgames-support] Add missing mnemonic

[Michael Catanzaro <mcatanzaro src gnome org>]

commit 4c4f0a8eb13aba8f01157bd8ceecf3578cb6eb82
Author: Michael Catanzaro <mcatanzaro gnome org>
Date:   Sat Feb 20 22:34:09 2016 -0600

    Add missing mnemonic

 games/scores/dialog.vala |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)
---
diff --git a/games/scores/dialog.vala b/games/scores/dialog.vala
index c8f918a..1260c75 100644
--- a/games/scores/dialog.vala
+++ b/games/scores/dialog.vala
@@ -160,7 +160,7 @@ private class Dialog : Gtk.Dialog
 
         if (new_high_score != null)
             /* Appears on the top right corner of the dialog. Clicking the button closes the dialog. */
-            add_button (_("Done"), Gtk.ResponseType.OK).get_style_context ().add_class ("suggested-action");
+            add_button (_("_Done"), Gtk.ResponseType.OK).get_style_context ().add_class ("suggested-action");
 
         load_categories ();