Axel Huebl d1e7344f16 ClockEstimate: DivByZero
The clock estimator has a potential division by zero.
Using `iteration + 1` seems also more logical to me for
an average.

Found with coverity in a downstream project.
2019-01-11 11:55:51 +01:00
..
2019-01-11 11:55:51 +01:00