[Plugin: Delete pending comments] error message

I woke up to 1500 pending comments (I guess all spam) this morning. As, I believe, Akismet had an outage last night.

This is a really good plug-in however I got the following error message after I hit delete.

Warning: Missing argument 2 for wpdb::prepare(), called in public_html/wp-content/plugins/delete-pending-comments/inc/admin.php on line 73 and defined in public_html/wp-includes/wp-db.php on line 992

However all pending comments were deleted successfully, thank you.