Remove -fvisibility=hidden when compiling c-ares
Remove -fvisibility=hidden when compiling c-ares

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