[FLINK-10395][build] Remove lefover 'codebase' references

pom.xml

@@ -128,7 +128,6 @@ under the License.
  <powermock.version>2.0.0-RC.4</powermock.version>
  <hamcrest.version>1.3</hamcrest.version>
  <japicmp.skip>false</japicmp.skip>
- <codebase>new</codebase>
  <!--
  Keeping the MiniKDC version fixed instead of taking hadoop version dependency
  to support testing Kafka, ZK etc., modules that does not have Hadoop dependency
@@ -1389,7 +1388,6 @@ under the License.
  <systemPropertyVariables>
  <forkNumber>0${surefire.forkNumber}</forkNumber>
  <log4j.configuration>${log4j.configuration}</log4j.configuration>
- <codebase>${codebase}</codebase>
  </systemPropertyVariables>
  <argLine>-Xms256m -Xmx2048m -Dmvn.forkNumber=${surefire.forkNumber} -XX:+UseG1GC</argLine>
  </configuration>