Ignore non-participating probes

[alyxto]

It would be great to have an option to ignore results from probes which are no longer participating in a measurement.

I have removed a probe from a measurement which is reporting false reports due to issues with the probe network itself.
Removing the probe results in it not participating in the measurement any more, but it still is visible in the measurement (just marked as non participating)

The exporter seems to just continue logging the last result from the probe, even though it's not doing any measurements any more.