remove argument of phonebook_ldap() hook

It is not used anywhere, and since we call the hook without argument it
would return an php error anyway

application/plugins/phonebook_ldap/phonebook_ldap.php

@@ -28,7 +28,7 @@ public function __construct()
 	 * with modification
 	 *
 	 */
-	function phonebook_ldap($number)
+	function phonebook_ldap()
 	{
 		if ( ! extension_loaded('ldap'))
 		{