update CHANGES.txt for HADOOP-8814

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/trunk@1512515 13f79535-47bb-0310-9956-ffa450edef68
HADOOP-9857. Tests block and sometimes timeout on Windows due to invalid entropy source. Contributed by Chris Nauroth.

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/trunk@1512522 13f79535-47bb-0310-9956-ffa450edef68