[connman] dnsproxy: Prefer responses with ancount>0 if append_domain is true

If domain_append is true and a valid domain tld (eg. com. net. bz.) is queried we need to make sure that responses with ancount>0 are preferred over ones with ancount==0. This is due queries againts valid domain tld's will always have response code ns_r_noerror even there are no valid records. This will solve the issue dnsproxy not returning the expected response if hostname queried is equal to any valid tld.