Updated Urlshortener.php

This change has been generated by a script that has detected changes in the
discovery doc of the API.

Check http://developers.google.com/discovery for more info.

Author: silvolu

src/Google/Service/Urlshortener.php

@@ -23,7 +23,7 @@
  *
  * <p>
  * For more information about this service, see the API
- * <a href="http://github.com/%3Cspan%20class="x x-first x-last">http://code.google.com/apis/urlshortener/v1/getting_started.html" target="_blank">Documentation</a>
+ * <a href="http://github.com/%3Cspan%20class="x x-first x-last">https://developers.google.com/url-shortener/v1/getting_started" target="_blank">Documentation</a>
  * </p>
  *
  * @author Google, Inc.