Adding Matt Hortman to list of contributors.

guacamole-common-js/src/main/resources/guacamole.js

@@ -20,6 +20,7 @@
  * the Initial Developer. All Rights Reserved.
  *
  * Contributor(s):
+ * Matt Hortman
  *
  * Alternatively, the contents of this file may be used under the terms of
  * either the GNU General Public License Version 2 or later (the "GPL"), or