Add HADOOP-7106 to CHANGES.txt for 0.21.

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-0.21@1135003 13f79535-47bb-0310-9956-ffa450edef68
3 files changed
tree: ff199e934132da095ad7eebe0e18ca20700578d7
  1. common/
  2. hdfs/
  3. mapreduce/