A possibile solution / workaround could be to re-put Chiasso in the promotion league (not sure if the club still exist in the db) and give them something like a -90 points deduction or similar, so the will be relegated for sure... not sure if that's possible though.
I did take a look in the db and I'm not sure if Chiasso is still there; in "real life" their future is still unclear - first league, second, merge with other club(s), start from 0 .. ¯\_(ツ)_/¯