add download_data method for ftp_handler
add download_data method for ftp_handler

quarkslab/irma,quarkslab/irma,hirokihamasaki/irma,hirokihamasaki/irma,hirokihamasaki/irma,quarkslab/irma,hirokihamasaki/irma,quarkslab/irma,hirokihamasaki/irma