TestHadoop20SAuthBridge uses DefaultImpersonationProvider (2.4.0 -> 2.6.0 API change)

[ERROR] Failed to execute goal org.apache.maven.plugins:maven-compiler-plugin:3.1:testCompile (default-testCompile) on project hive-it-unit-hadoop2: Compilation failure: Compilation failure:
[ERROR] /data/hive-ptest/working/apache-svn-trunk-source/itests/hive-unit-hadoop2/src/test/java/org/apache/hadoop/hive/thrift/TestHadoop20SAuthBridge.java:[134,49] non-static method getProxySuperuserIpConfKey(java.lang.String) cannot be referenced from a static context
[ERROR] /data/hive-ptest/working/apache-svn-trunk-source/itests/hive-unit-hadoop2/src/test/java/org/apache/hadoop/hive/thrift/TestHadoop20SAuthBridge.java:[297,35] non-static method getProxySuperuserGroupConfKey(java.lang.String) cannot be referenced from a static context