UIMA-3599 DUCC Job Driver (JD) does not unregister re-used CAS's from the callback tracker map

git-svn-id: https://svn.apache.org/repos/asf/uima/sandbox/uima-ducc/branches/uima-ducc-1.0.0@1568966 13f79535-47bb-0310-9956-ffa450edef68