QPID-5048: override the parent pom property to keep using junit 3.8.1 until QPID-5702 is applied

merge from trunk r1588895


git-svn-id: https://svn.apache.org/repos/asf/qpid/branches/0.28@1588908 13f79535-47bb-0310-9956-ffa450edef68