resolved: don't treat conn reset as packet loss

resolved: don't treat conn reset as packet loss

tcp reset / icmp port-unreachable are markedly different conditions than
packet loss. It doesn't make much sense to retry in this case. It's
actually not clear if there is any benefit at all retrying tcp
connections, which were presumably already retried as necessary by the
tcp stack.

(cherry picked from commit ddd710a355acc698b48159f3e501dda5a7dc2704)