message: Add another curl spurious network error
  Witnessed in a [recent build][1] looks like this is another error that
  should be safe to retry.
  [1]:
diff: @@ -52,6 +52,7 @@ fn maybe_spurious(err: &Error) -> bool {
  || curl_err.is_recv_error()
  || curl_err.is_http2_stream_error()
  || curl_err.is_ssl_connect_error()
  + || curl_err.is_partial_file()
  {
  return true;
  }
  