* serve restic: return internal error if listing failed
If listing a remote failed, then rclone returned http status "not
found". This has become a problem since restic 0.16.0 which ignores "not
found"-errors while listing a directory.
Just return internal server error, if something unexpected happens while
listing a directory.
* serve restic: fix error handling if getting a file fails
If the call to `newObject` in `serveObject` fails, then rclone always
returned a "not found" error. This prevents restic from distinguishing
permanent "not found" errors from everything else.
Thus, only return "not found" if the object is not found and an internal
server error otherwise.
ef2c5a1998