Improved handling of proxy file in HTCondor backend (fixes BUGZ-3824)
Changes to HTCondor backend in respect to proxy handling:
- consistent with other backends behavior to transfer proxy to WN only if ENV/PROXY had been requested (or used as default RTE).
- proxy exported/copied by ENV/PROXY is used instead of the path to controldir file. This will work with delegation db and planned proxy handling improvements.
- all session directory, in case it is not shared between ARC CE and WNs, is transferred now, consistently to other backends. For proxy case this means CA certificates exported by ENV/PROXY will be included.