fix breadcrumb retrieval from external cache manager
fix breadcrumb retrieval from external cache manager

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