Change blah parser to use first FQAN in log line

- Add logic blah parser when the split line is stored in a dictionary to
  only store values that do not already have a key in the dictionary. This
  is so that only the first userFQAN is stored as this is the primary FQAN
  that should be used in accounting (rather than before where the last one
  was used, which led to VORole usually being NULL for multiple FQANs).