bpf/proxy: fix stale NAT entries cleanup
bpf/proxy: fix stale NAT entries cleanup

When nodeport is forwarded to another node, it does not have the first
node's IP in its tables, therefore it thinks that the conntrack entries
are for a service that is gone. We also need to match against the
wildcard to check if the front end might be a nodeport.

neiljerram/felix,neiljerram/felix,Metaswitch/calico,Metaswitch/calico,neiljerram/felix,neiljerram/felix