invalid dnsname about hyper-rustls HOT 8 CLOSED

let path = "D:\\workSpace\\myrust\\rust-demo\\web_tcp\\config\\sample.pem";
let f = fs::File::open(path)
    .map_err(|e| error(format!("failed to open {}: {}", path, e)))?;
let rds = io::BufReader::new(f);
let mut ca = Some(rds);
// Prepare the HTTPS connector.
println!("读取证书完成");
let https = match ca {
    Some(ref mut rd) => {
        // Build an HTTP connector which supports HTTPS too.
        let mut http = client::HttpConnector::new(4);
        http.enforce_http(false);
        // Build a TLS client, using the custom CA store for lookups.
        let mut tls = rustls::ClientConfig::new();
        tls.root_store
            .add_pem_file(rd)
            .map_err(|_| error("failed to load custom CA store".into()))?;
        // Join the above part into an HTTPS connector.
        hyper_rustls::HttpsConnector::from((http, tls))
    }
    // Default HTTPS connector.

    None => {
        println!("证书有问题!");
        hyper_rustls::HttpsConnector::new(4)
    }
};