Added: New string in config!
Now if NickNameRepeat is true, then if player join with name which use letters like a nickname registered player he/she was kicked. Ex.: player Kolay2 already registered in server, but join player with nick koLAy2 some plugins cant understand diffierence Kolay2 and koLAy2 and add rights which have Kolay2. But if NickNameRepeat is true koLAy2 be kicked from server, else if NickNameRepeat is false koLAy2 and Kolay2 can play together (is okey if all plugins use UUID, but bad if some plugins in server use nicknames for player events).