`Statistic duration bug: attempted to add a statistic with a duration less than 1.`

[bitjson]

This will probably be solved by #18, but somehow block downloads are occasionally completing with a negative duration... We're just ignoring statistics from those downloads, but we should track down why that's happening.

https://github.com/bitauth/chaingraph/blob/cbebedefea908957b0373d77a60ec17fdff2050b/src/components/throughput-statistics.ts#L97-L114