CVE-2021-22890: TLS 1.3 session ticket proxy host mixup

Summary: (I don't think that this can be easily exploitable, but I am submitting it as a security issue for precaution. I am not looking for a bounty.)

const bool isProxy = CONNECT_PROXY_SSL();
struct ssl_primary_config * const ssl_config = isProxy ?
  &conn->proxy_ssl_config :
  &conn->ssl_config;
const char *hostname = isProxy ? conn->http_proxy.host.name :
  conn->host.name;