DERBY-6248; nightly regression test failure: testDerby966(org.apache.derbyTesting.functionTests.tests.jdbcapi.XATest)java.sql.SQLFeatureNotSupportedException: The DDM object 0x2408 is not supported.  The connection has been terminated.
   merge of revision 1578192 from trunk; adding a rollback to work around the issue


git-svn-id: https://svn.apache.org/repos/asf/db/derby/code/branches/10.8@1589515 13f79535-47bb-0310-9956-ffa450edef68