Remove unused methods on SessionHandler

[janbartel]

jetty-10

I don't think these methods are used and so should be removed:

/**
* @return true if the cluster node id (worker id) is returned as part of the session id by {@link HttpSession#getId()}. Default is false.
*/
public boolean isNodeIdInSessionId()
{
return _nodeIdInSessionId;
}

/**
 * @param nodeIdInSessionId true if the cluster node id (worker id) will be returned as part of the session id by {@link HttpSession#getId()}. Default is false.
 */
public void setNodeIdInSessionId(boolean nodeIdInSessionId)
{
    _nodeIdInSessionId = nodeIdInSessionId;
}