Fix a GCC 10.0.1 compilation error.
Do not try to stuff "HS_DESC_DECODE_GENERIC_ERROR" (-1) into a socks5_reply_status_t (enum). It doesn't actually make sense, and isn't one of our documented extensions. (This can only happen on a nonfatal assertion that we haven't seen, so it probably isn't happening in practice.) Fixes another case of bug 34077; bugfix on 0.4.3.1-alpha.