[Bug] Output file sometimes reports 0 for Ops/sec, latency, etc, in the Totals section (even though traffic occurred)

[DrEsteban]

This seems to happen more often on higher connection count tests, but we've seen it occasionally on lower connection counts as well.

This may be related to #271, and resolved by #273, but logging it as a separate issue just in case!

Example output file:
test-run-upload.json

@filipecosta90

[filipecosta90]

Fixed by #273