public void setLoginRestrictedToNickname(boolean restricted) {
        this.loginRestrictedToNickname = restricted;
    }
Sets if registered users can only join the room using their registered nickname. A
not_acceptable error will be returned if the user tries to join the room with a nickname
different from the reserved nickname.

@param restricted if registered users can only join the room using their registered nickname.
xmppserver/src/main/java/org/jivesoftware/openfire/muc/MUCRoom.java