Add info about blocking x_tables module when using nf_tables

According to website https://wiki.nftables.org/wiki-nftables/index.php/Moving_from_iptables_to_nftables you should not use x_tables (iptables) and nf_tables (nftables) kernel modules at the same times. At the bottom of the page there is this:

Beware of using both the nft and the legacy tools at the same time. That means using both x_tables and nf_tables kernel subsystems at the same time, and could lead to unexpected results.

I suggest to add info about blocking module x_tables to the section about nftables on the page https://docs.voidlinux.org/config/network/firewalls.html .

On my personal computer with void linux I created file /etc/modprobe.d/iptables-blacklist.conf with content:

blacklist x_tables
install x_tables /bin/false

Seems to block x_tables effectively.

Commencez par la section nftables de la source mdBook qui est rendue sous la forme de docs.voidlinux.org/config/network/firewalls.html, puis lisez le guide de migration nftables indiqué par le lien. Le travail est terminé lorsque la page explique le conflit entre x_tables et nf_tables et inclut la configuration modprobe proposée, et que la compilation de la documentation ou la page rendue a été vérifiée.