after parse use edns_opt_find(edns.opt_list, LDNS_EDNS_NSID),
to insert use edns_opt_append(edns, region, code, len, bindata) on
the opt_list passed to send_query, or in edns_opt_inplace_reply.
git-svn-id: file:///svn/unbound/trunk@3742 be551aaa-1e26-0410-a405-d3ace91eadb9