未捕获的异常'GuzzleHttp \ Exception \ RequestException'，消息'cURL错误60

I tried google oauth php on my localhost and got this error!What can I do

Uncaught exception 'GuzzleHttp\Exception\RequestException' with message 'cURL error 60: SSL certificate problem: unable to get local issuer certificate (see

http://curl.haxx.se/libcurl/c/libcurl-errors.html)' in C:\wamp\www\google\vendor\guzzlehttp\guzzle\src\Handler\CurlFactory.php

on line 187

1. Download ca fiile "curl http://curl.haxx.se/ca/cacert.pem -o cacert.pem"
2. My file "cacert.pem" move to "/wwwroot/ca/cacert.pem"
3. Open file php.ini, enable openssl, and find "openssl.cafile", set "openssl.cafile=/wwwroot/ca/cacert.pem"
4. Restart web server(nginx/apache) or reopen terminal.
5. Enjoy.