AVRO-1439. Fix to work when -Dhadoop.version=2.
Hadoop2 depends on Commons Codec 1.3, while Hadoop1 depends on 1.4.


git-svn-id: https://svn.apache.org/repos/asf/avro/trunk@1564903 13f79535-47bb-0310-9956-ffa450edef68