https://developer.mozilla.org/en-US/docs/Web/API/CloseEvent
#include "pch.h"请参阅：Browser compatibility
示例chrome（版本71.0）返回1006错误，firefox（版本64.0（64位））1015：
1015 TLS Handshake Reserved. Indicates that the connection was closed due to a failure to perform a TLS handshake (e.g., the server certificate can't be verified).