path_findings() flagged ICMP rate limiting as real loss whenever two
consecutive traceroute hops both went silent, but real transit paths
routinely have long runs of silent hops (10 in a row, confirmed on a live
--full run) while the destination itself answers cleanly. Only flag loss
that persists all the way to the last hop in the trace; a run that clears
before the end is now ignored regardless of how many hops it spans.
a hop with no icmp reply has ip=None; the sustained-loss finding
formatted it straight into the report text as the literal string
'(None)'. seen live in a --quick smoke test report.
