Move HDFS-4680 in CHANGES.txt

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/trunk@1522049 13f79535-47bb-0310-9956-ffa450edef68
YARN-1176. RM web services ClusterMetricsInfo total nodes doesn't include unhealthy nodes (Jonathan Eagles via tgraves)

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/trunk@1522062 13f79535-47bb-0310-9956-ffa450edef68