HDFS-14958. TestBalancerWithNodeGroup is not using NetworkTopologyWithNodeGroup. Contributed by Jim Brennan.

hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/server/balancer/TestBalancerWithNodeGroup.java

@@ -82,6 +82,7 @@ public class TestBalancerWithNodeGroup {
     Configuration conf = new HdfsConfiguration();
     TestBalancer.initConf(conf);
     conf.setLong(DFSConfigKeys.DFS_BLOCK_SIZE_KEY, DEFAULT_BLOCK_SIZE);
+    conf.setBoolean(DFSConfigKeys.DFS_USE_DFS_NETWORK_TOPOLOGY_KEY, false);
     conf.set(CommonConfigurationKeysPublic.NET_TOPOLOGY_IMPL_KEY, 
         NetworkTopologyWithNodeGroup.class.getName());
     conf.set(DFSConfigKeys.DFS_BLOCK_REPLICATOR_CLASSNAME_KEY,