ZOOKEEPER-1179. NettyServerCnxn does not properly close 
  socket on 4 letter word requests (Rakesh R, Germán Blanco 
  via fpj)



git-svn-id: https://svn.apache.org/repos/asf/zookeeper/branches/branch-3.4@1553672 13f79535-47bb-0310-9956-ffa450edef68