Fix an overflow check
Fix an overflow check

Tor internally multiplies our values by 1000, and silently eats the overflow.

Why do we bother dividing them by 1000 in the first place? It just causes
confusion and bugs.. The git blame log and comments mumble something about
consensus diffs, but I think we gave up on those...

isislovecruft/torflow,isislovecruft/torflow,isislovecruft/torflow,isislovecruft/torflow