If the server sent the whole file, or a different range, in response
to a ranged download rclone returned it as if it were the requested
range, which gave wrong data when seeking.
Check the response with rest.CheckContentRange and return an error if
it doesn't satisfy the requested range. fs.ErrorRangeIgnored lets
multi-thread copies fall back to a single stream.
This guards against Graph serving downloads itself after the
retirement of pre-authenticated (tempauth) URLs.
See: #10070
Nick Craig-Wood
2b4cb5f85b