use correct hash of empty string for autocatalog markers
use correct hash of empty string for autocatalog markers

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