TestLoopContinuesAfterObserverError was failing due to system
granularity measuring the duration as 0.
TestDialer_DialTimeout was failing due to connection failure came with a
delay and wasn't being handled.
Change-Id: I4638c86f5d021a86c3d3529fab13cf3608f35c40
Support interruption of the ranged segment loop through context.
Part of https://github.com/storj/storj/issues/5223
Change-Id: Iae0260e250f8ea33affed95c6592a1f42df384eb