tw_ee_filter_ics_data.php

<?php
//* Please do NOT include the opening php tag, except of course if you're starting with a blank file

add_filter(
  'FHEE__EED_Ical__download_ics_file_ics_data',
  'tw_ee_filter_ics_data',
  10,
  2
);

function tw_ee_filter_ics_data(
    $ics_data, 
    $datetime
) {
    unset($ics_data['URL;VALUE=URI'])
    return $ics_data;
}