remove small memory leak when verifying manifest
remove small memory leak when verifying manifest

DrDaveD/cvmfs,djw8605/cvmfs,Gangbiao/cvmfs,cvmfs/cvmfs,trshaffer/cvmfs,alhowaidi/cvmfsNDN,djw8605/cvmfs,alhowaidi/cvmfsNDN,trshaffer/cvmfs,trshaffer/cvmfs,alhowaidi/cvmfsNDN,DrDaveD/cvmfs,Gangbiao/cvmfs,Gangbiao/cvmfs,DrDaveD/cvmfs,trshaffer/cvmfs,DrDaveD/cvmfs,djw8605/cvmfs,cvmfs/cvmfs,alhowaidi/cvmfsNDN,alhowaidi/cvmfsNDN,DrDaveD/cvmfs,djw8605/cvmfs,cvmfs/cvmfs,djw8605/cvmfs,Gangbiao/cvmfs,cvmfs/cvmfs,DrDaveD/cvmfs,trshaffer/cvmfs,cvmfs/cvmfs,Gangbiao/cvmfs,DrDaveD/cvmfs,cvmfs/cvmfs,cvmfs/cvmfs