FIX: proper thread destruction in SynchronizingCounter test
FIX: proper thread destruction in SynchronizingCounter test

cvmfs/cvmfs,Moliholy/cvmfs,alhowaidi/cvmfsNDN,DrDaveD/cvmfs,alhowaidi/cvmfsNDN,Moliholy/cvmfs,cvmfs-testing/cvmfs,reneme/cvmfs,alhowaidi/cvmfsNDN,cvmfs/cvmfs,DrDaveD/cvmfs,Gangbiao/cvmfs,reneme/cvmfs,MicBrain/cvmfs,Gangbiao/cvmfs,DrDaveD/cvmfs,trshaffer/cvmfs,trshaffer/cvmfs,MicBrain/cvmfs,cvmfs/cvmfs,reneme/cvmfs,Gangbiao/cvmfs,cvmfs-testing/cvmfs,cvmfs-testing/cvmfs,Gangbiao/cvmfs,MicBrain/cvmfs,cvmfs/cvmfs,DrDaveD/cvmfs,cvmfs/cvmfs,cvmfs/cvmfs,cvmfs-testing/cvmfs,DrDaveD/cvmfs,alhowaidi/cvmfsNDN,trshaffer/cvmfs,Moliholy/cvmfs,djw8605/cvmfs,Moliholy/cvmfs,MicBrain/cvmfs,trshaffer/cvmfs,cvmfs-testing/cvmfs,djw8605/cvmfs,alhowaidi/cvmfsNDN,reneme/cvmfs,Moliholy/cvmfs,reneme/cvmfs,Gangbiao/cvmfs,MicBrain/cvmfs,cvmfs/cvmfs,DrDaveD/cvmfs,djw8605/cvmfs,djw8605/cvmfs,djw8605/cvmfs,trshaffer/cvmfs,DrDaveD/cvmfs