gresolv: Do not update successful status with unsuccessful one

gresolv: Do not update successful status with unsuccessful one

When performing a resolver lookup from timeserver or wpad, both perform
queries with an unspecified address family. This means that both A and
AAAA record queries are issued. In cases where a valid, successful A
response comes back but where the AAAA query results in a timeout, do
not smash the successful A status with the time out AAAA status;
otherwise, the timeserver or wpad will appear to fail to them when, in
fact, the A query was successful and more than satisfies its unspecified
address family requirement.

Partial fix for BMC#25486.