[php-src] Issue #8226: php.net blocks nbftp user-agent

Issue: https://github.com/php/php-src/issues/8226 Author: johnklos ### Description When NetBSD's wget-like command line ftp program (called nbftp) attempts to fetch php tarballs, an error is returned: ```ftp "https://www.php.net/distributions/php-8.0.17.tar.xz" Trying [2a02:cb40:200::1ad]:443 ... Requesting https://www.php.net/distributions/php-8.0.17.tar.xz ftp: Error retrieving file `503 Service Temporarily Unavailable' ``` On the same machine, wget succeeds, so it appears the web servers are blocking nbftp's user-agent (NetBSD-ftp/20210826, where 20210826 is the version). Although this is a web server issue and not a php issue, I cannot contact the webmasters as listed on https://www.php.net/contact.php because the address there requires senders be subscribed. ### PHP Version All ### Operating System NetBSD