Golang获取https公钥crt格式

	c := http.Client{
		Transport: &http.Transport{
			TLSClientConfig: &tls.Config{InsecureSkipVerify: true},
		},
	}
	resp, err := c.Get("https://harbor.abc.com:8443/")
	if err != nil {
		panic(err)
	}
	cert := resp.TLS.PeerCertificates[0]
	pem.Encode(os.Stdout, &pem.Block{
		Type: "CERTIFICATE",
		Bytes: cert.Raw,
	})