[warn] tor_timegm(): Bug: Out-of-range argument to tor_timegm

moria1, running Tor 0.2.5.0-alpha-dev (git-8f0755fa85b9c1fb), once saw

Jul 25 02:55:01.546 [warn] tor_timegm(): Bug: Out-of-range argument to tor_timegm

No other hints, at info-level, around it. I assume maybe it came in a descriptor of some sort, or a netinfo or something.

Bug #6811 (moved) looks like the last time we touched this stuff, but it was a while ago.

Should this turn into a log-protocol-warn when it's based on network input? In any case, it's not a Bug:, right? Unless we think there's a code path where it is?