HADOOP-8878. uppercase namenode hostname causes hadoop dfs calls with webhdfs filesystem and fsck to fail when security is on  (Arpit Gupta via tgraves)

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-0.23@1441236 13f79535-47bb-0310-9956-ffa450edef68