fix flakey unit test
fix flakey unit test

DrDaveD/cvmfs,DrDaveD/cvmfs,cvmfs/cvmfs,DrDaveD/cvmfs,DrDaveD/cvmfs,DrDaveD/cvmfs,cvmfs/cvmfs,DrDaveD/cvmfs,cvmfs/cvmfs,DrDaveD/cvmfs,cvmfs/cvmfs,cvmfs/cvmfs,cvmfs/cvmfs,cvmfs/cvmfs