Add branch-2 only commit HDFS-7138 to CHANGES.txt

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

@@ -577,6 +577,8 @@ Release 2.6.0 - UNRELEASED
 
     HDFS-7139. Unit test for creating encryption zone on root path. (Zhe Zhang via wang)
 
+    HDFS-7138. Fix hftp to work with encryption. (clamb via wang)
+
   OPTIMIZATIONS
 
     HDFS-6690. Deduplicate xattr names in memory. (wang)