Update CHANGES.txt for HDFS-4739.

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-2@1471775 13f79535-47bb-0310-9956-ffa450edef68

hadoop-hdfs-project/hadoop-hdfs/CHANGES.txt

@@ -206,6 +206,9 @@ Release 2.0.5-beta - UNRELEASED
 
     HDFS-4737. JVM path embedded in fuse binaries. (Sean Mackrory via atm)
 
+    HDFS-4739. NN can miscalculate the number of extra edit log segments to
+    retain. (atm)
+
 Release 2.0.4-alpha - UNRELEASED
 
   INCOMPATIBLE CHANGES