Update Copyright headers

src/hb-unicode.cc

diff --git a/src/hb-unicode.cc b/src/hb-unicode.cc
index 282a9b6..14285ec 100644
--- a/src/hb-unicode.cc
+++ b/src/hb-unicode.cc
@@ -1,7 +1,7 @@
 /*
- * Copyright (C) 2009  Red Hat, Inc.
+ * Copyright © 2009  Red Hat, Inc.
  * Copyright © 2011 Codethink Limited
- * Copyright (C) 2010  Google, Inc.
+ * Copyright © 2010,2011  Google, Inc.
  *
  *  This is part of HarfBuzz, a text shaping library.
  *