0pdd: Comment contains "#unknown are still not solved"

When 0pdd adds a comment to a parent issue about number of not solved puzzles, the comment may contain #unknown are still not solved that is, as I suspect, a bug.

Example:

19 puzzles #839, #841, #842, #846, #847, #849, #851, #852, #853, #854, #855, #856, #859, #861, #863, #865, #866, #867, #unknown are still not solved; solved: #833, #834, #835, #836, #838, #840, #843, #844, #848, #860, #864.

Seen there: https://github.com/php-coder/mystamps/issues/695#issuecomment-405372820