BUG/MINOR: resolvers: fix memory leak on AAAA additional records

BUG/MINOR: resolvers: fix memory leak on AAAA additional records

Commit c84c15d3938a ("BUG/MINOR: resolvers: Apply dns-accept-family
setting on additional records") converted a switch statement to an
if/else chain but left the break; in the AAAA branch. In the new
form, break exits the surrounding for loop instead of a switch case.

For every AAAA additional record in an SRV response:
  - answer_record allocated at line 1460 is never freed and never
    inserted into answer_tree -> ~580 bytes leaked per response
  - all subsequent additional records in the response are silently
    discarded

A DNS server controlling SRV responses for haproxy service discovery
can leak memory at MB/min rates given default resolution intervals.
Also breaks IPv6 SRV target resolution outright since the AAAA record
is leaked rather than attached to its SRV entry.