common: bump nf_conntrack_max to 256k on redirect

The traffic hitting ping.archlinux.org has lately been exhausting its default nf_conntrack_max limit of 64k. Bump it to 256k (which is also the default limit found on systems with more than 4G of memory).

Suggested-by: Kristian Klausen kristian@klausen.dk

host_vars/redirect.archlinux.org/misc

@@ -4,3 +4,6 @@ wireguard_public_key: n11Ps2sc0Cxsi1sLaYFq7dkhlDtTnOZCGovRYbzDGR8=
 
 ipv4_address: "95.216.195.133"
 ipv6_address: "2a01:4f9:c010:2636::1"
+
+# The default limit of 65536 is too small to handle ping.archlinux.org traffic
+nf_conntrack_max: 262144