MAPREDUCE-5761. Added a simple log message to denote when encrypted shuffle is on in the shuffle-handler. Contributed by Jian He.
svn merge --ignore-ancestry -c 1571514 ../../trunk/


git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-2.4@1571516 13f79535-47bb-0310-9956-ffa450edef68