gresolv: Destroy query at the relevant place when parsing the response

gresolv: Destroy query at the relevant place when parsing the response

parse_response() will eventually call sort_and_return_results() which in turn
will call the result function. But the result function might cancel the gresolv.
At that point all queries belonging to this gresolv are destroyed. Returning back
to parse_response(), it calls again destroy_query() on an already destroyed one.
Thus leading to a crash.

Same issue with query_timeout()

Reported by Daniel Wagner