message: Make AliDataFile ignore AliPhysics version tags
  When looking for data files on CVMFS, ignore any version tag that comes after
  an underscore. If version is `vAN-20181021_ROOT6-1`, then it is converted to
  `vAN-20181021`: both build number and the `_ROOT6` tag are ignored.
diff: @@ -15,14 +15,15 @@ std::string AliDataFile::GetFileName(const std::string &url) {
  // /cvmfs/alice.cern.ch/data/analysis/YYYY/VVVV/<url>
  std::string buf, ver, year;
  - size_t dash;
  const char *env;
  if ((env = gSystem->Getenv("ALIPHYSICS_VERSION"))) {
  buf = env;
  - dash = buf.rfind('-');
  - if (dash != std::string::npos) {
  - ver = buf.substr(0, dash);
  + size_t cut = buf.rfind('-'); // remove build number
  + size_t us = buf.rfind('_');
  + if (cut != std::string::npos) {
  + if (us != std::string::npos && us < cut) cut = us;
  + ver = buf.substr(0, cut);
  if (buf.length() >= 12 && buf.substr(0, 4) == "vAN-") year = buf.substr(4, 4);
  }
  }
  