QPID-5624: Bug fix - derby must allow absence of configuration store settings

git-svn-id: https://svn.apache.org/repos/asf/qpid/branches/java-broker-bdb-ha2@1578832 13f79535-47bb-0310-9956-ffa450edef68
Temporary change to pom.xml to clean broker between tests - change will come from trunk as part of Maven work

git-svn-id: https://svn.apache.org/repos/asf/qpid/branches/java-broker-bdb-ha2@1578833 13f79535-47bb-0310-9956-ffa450edef68