MDL-57775 xmlrpc: Formal fix of coding style and phpdocs

- There was missing MOODLE_INTERNAL check.
- The client is not used for unit tests only so the class description
  was obsolete.

webservice/xmlrpc/lib.php

@@ -14,7 +14,6 @@
 // You should have received a copy of the GNU General Public License
 // along with Moodle.  If not, see <http://www.gnu.org/licenses/>.
 
-
 /**
  * Moodle XML-RPC library
  *
@@ -23,11 +22,11 @@
  * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  */
 
+defined('MOODLE_INTERNAL') || die();
+
 /**
  * Moodle XML-RPC client
  *
- * It has been implemented for unit testing purpose (all protocols have similar client)
- *
  * @package    webservice_xmlrpc
  * @copyright  2010 Jerome Mouneyrac
  * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later