Try and use a SciToken before using X509
Created by: duncan-brown
This pull request add the ability to use a SciToken before trying to use X509 certificates when talking to the segment database. The SciToken is looked for in:
- The contents of the file
${_CONDOR_CREDS}/scitokens.use
- The contents of the file pointed to by the environment variable
${SCITOKENS_FILE}
- The contents of the environment variable
${SCITOKENS}
If a SciToken is not found, X509 authentication is used.