Bot stops working when message limit exceeds  #21

When someone adds someone to a list and the message length exceeds, it pops error "Modifiers are invalid" and doesnt add player to a message. After that, when trying to press "next turn", bot stops working and pops "unknown error". It may be due to a thing that bot doesnt add player to a discord message, but adds it to a internal table.

My idea to fix it: add a character length limit (50?) and limit visible players on list (20?)