We can't use dnat from the input hook,
depending on nftables (and kernel ?) version we get
"Error: Could not process rule: Operation not supported"
iptables backend also uses prerouting.
Also 'ip6 protocol tcp' is invalid, so rework / simplify the rules
Fixes 01a94e17c7
Signed-off-by: Etienne Champetier <e.champetier@ateme.com>
