Add default return value for CURLINFO_CERTINFO

[clemherreman]

Context

symfony/http-client is using the cURL CURLINFO_CERTINFO (see here)

However PHP-VCR is not handling this. By default, its value is [], unless a developer use this:

curl_setopt($ch, CURLOPT_CERTINFO, 1);
curl_setopt($ch, CURLOPT_VERBOSE, 1);

What has been done

This PR allows curl_getinfo($ch, CURLINFO_CERTINFO) to return the default cURL value : [] when those curl_setopt are not set, instead of a PHP VCR Exception.

How to test

I added a test to CurlHelperTest, testing that calling curl_getinfo($ch, CURLINFO_CERTINFO) doesn't thrown an exception, but returns the default cURL value.

Notes

Build is failing because of PHP CS Fixer on files unrelated to this PR. As multiple PRs include that fix, I didn't run the fix again on this one :)