Well, how long has it been flowering? If it's been flowering for more than a week then leave it, because you'll stress it so much it'd probably turn hermie.

If it has litteraly been in flowering for a cuple of days, stick the lights on 18/6 and it should revert, but it'll take time.

The plant buds by measuring the un-interuppted darkness, which realeases a flowering hormone. You dont wanna start confusing the plant, cos it'll just tell you to fuck right off lol.