Fix copyright notice in org-bibtex.el

lisp/org-bibtex.el

@@ -1,6 +1,6 @@
 ;;; org-bibtex.el --- Org links to BibTeX entries
 ;;
-;; Copyright 2007, 2008, 2009 Free Software Foundation, Inc.
+;; Copyright (C) 2007, 2008, 2009 Free Software Foundation, Inc.
 ;;
 ;; Author: Bastien Guerry <bzg at altern dot org>
 ;;         Carsten Dominik <carsten dot dominik at gmail dot com>