fix hang in unit tests
fix hang in unit tests

Gangbiao/cvmfs,cvmfs/cvmfs,trshaffer/cvmfs,DrDaveD/cvmfs,cvmfs/cvmfs,cvmfs/cvmfs,djw8605/cvmfs,DrDaveD/cvmfs,Gangbiao/cvmfs,Gangbiao/cvmfs,DrDaveD/cvmfs,trshaffer/cvmfs,Gangbiao/cvmfs,DrDaveD/cvmfs,djw8605/cvmfs,cvmfs/cvmfs,cvmfs/cvmfs,cvmfs/cvmfs,trshaffer/cvmfs,DrDaveD/cvmfs,trshaffer/cvmfs,djw8605/cvmfs,Gangbiao/cvmfs,djw8605/cvmfs,DrDaveD/cvmfs,DrDaveD/cvmfs,trshaffer/cvmfs,djw8605/cvmfs,cvmfs/cvmfs