Make hidden service port scanning harder by sending back REASON_DONE which
does not disclose that it was in fact an exit policy issue. After that, kill
the circuit immediately to avoid more bad requests on it.
This means that everytime an hidden service exit policy does match, the user
(malicious or not) needs to build a new circuit.
Fixes#13667.
Signed-off-by: David Goulet <dgoulet@ev0ke.net>
