Since the upgrade to FoxyProxy 8, firefox connects to sites using IPv6 even when network.dns.disableIPv6 is true. Version 7.5.1 (and presumably other older versions) would use IPv4 or IPv6, depending on network.dns.disableIPv6.

Steps to reproduce:

1. Use a dual-stack host running firefox and a dual-stack proxy (via socks5 and maybe other protocols).
2. Install FoxyProxy 8 (currently 8.7).
3. Import the proxy, e.g. as socks5://localhost:8801?title=test&proxyDns=false
4. Enable the proxy.
5. Configure firefox to have network.dns.disableIPv6 set to true.
6. Navigate to an IP-checker website, e.g. https://ifconfig.co/

Observed results:
The IP-checker website shows the client IP as an IPv6 IP.

Expected results:
The IP-checker website shows the client IP as an IPv4 IP.

Thanks,
Corey