Do not print message about missing file while retrieving job if file may be missing. BUGZ-4161.

Begin arcbot message
This merge request is automatically cherrypicked from !1806 (merged) from source branch https://source.coderefinery.org/aleksandr.konstantinov/arc/-/tree/suppress_messages_about_non_existing_files orginally made by @aleksandr.konstantinov .
The original MR went to branch: https://source.coderefinery.org/nordugrid/arc/-/tree/next
End arcbot message

Do not print message about missing file while retrieving job if file may be missing.