Error message

Warning: file_get_contents(https://subscribe.linphone.org/flexisip-account-manager/xmlrpc.php): failed to open stream: HTTP request failed! HTTP/1.1 404 Not Found in xml_rpc_request() (line 21 of /var/www/html/sites/all/modules/freesip.module/flexisip-account-manager-client-xmlrpc.php).