evaluate: reject: accept a reject reason with incorrect network context

evaluate: reject: accept a reject reason with incorrect network context

nft add rule bridge test-bridge input ether type ip \
				reject with icmpv6 type no-route

This rule pass the evaluation step but the network context is incompatible with
the reject reason. In that cases, we have to throw an error like "conflicting
protocols specified: ip vs ip6"

Signed-off-by: Alvaro Neira Ayuso <alvaroneay@gmail.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>