The brute force way to make the change is to go down to line 145 which looks like this
//find users with no posts & count published posts
$query = "SELECT COUNT(WP.ID) as recs, WU.ID
FROM {$tp}users WU
LEFT JOIN {$tp}posts WP ON WP.post_author = WU.ID AND NOT WP.post_type in ('attachment', 'revision') AND post_status = 'publish'
GROUP BY WU.ID";
and change it to this
//find users with no posts & count published posts
$query = "SELECT
COUNT(WP.ID) AS recs, COUNT(WC.comment_ID) AS comments, WU.ID
FROM {$tp}users WU
LEFT JOIN {$tp}posts WP ON WP.post_author = WU.ID AND NOT WP.post_type IN ('attachment', 'revision') AND post_status = 'publish'
LEFT JOIN {$tp}comments WC ON WC.user_id = WU.ID AND WC.comment_approved = 1
GROUP BY WU.ID
HAVING recs = 0 AND comments = 0";