[docs] ftp_ssl_connect peer-verification

[kronthto]

php.net has updated their documentation to state the fact that their function does not validate the certificate used in the SSL connection. php/doc-en#3915

flysystem/src/Ftp/FtpConnectionProvider.php

Line 46 in edc1bb7

$connection = $ssl ? @ftp_ssl_connect($host, $port, $timeout) : @ftp_connect($host, $port, $timeout);

The docs of this project are regarding SSL are sparse, merely advertising that the option exists.
I'm opening this issue to bring this fact to attention, as an user I assumed that 'ssl' => true is a "secure by default" option, which is not the case, so maybe this should at least be noted until an updated implementation becomes available.

(The PHP team was OK with handling this issue in public issuetrackers.)