Avoid resource leak in timestamp_infos

[ddelemeny]

Response.Body should be closed in any case

If the returned error is nil, the Response will contain a non-nil Body which the user is expected to close. If the Body is not both read to EOF and closed, the Client's underlying RoundTripper (typically Transport) may not be able to re-use a persistent TCP connection to the server for a subsequent "keep-alive" request.

https://pkg.go.dev/net/http#Client.Do