Use the proper encoding function in the relay server when constructing
the URL. In the pool server, parse and re-encode the query values to
sanitize whatever the client sent.
When cap(permanentRelays) >= len(permanentRelays) + len(knownRelays),
append(permanentRelays, knownRelays...)
returns a slice of the array underlying permanentRelays. The subsequent
rand.Shuffle then mixes the permanent and known relays. Sequential
requests may cause strelaypoolsrv to forget its permanent relays. Worse,
concurrent requests may cause shuffling of the same slice on multiple
processors concurrently.
Co-authored-by: greatroar <@>
