Fixed deprecated value for CURLOPT_SSL_VERIFYHOST

CURLOPT_SSL_VERIFYHOST has a deprecated value assigned. 

Currently it produces notices:

```bash
Notice: curl_setopt(): CURLOPT_SSL_VERIFYHOST with value 1 is deprecated and will be removed as of libcurl 7.28.1. It is recommended to use value 2 instead in .../S3.php on line 1762
```