feedpositionAnalyzer: set metrics to 0 when source not at night time

[nritsche]

In line 228, set all metrics to 0 that use source as a label. Otherwise the value stays at what it was the last time this source was found to be at night time.

[cahofer]

If I understand correctly, then I think we should set the metrics all to zero when analyzer is run? e.g. in line 223
self.percent_metric.labels(source=src).set(0)
self.freq_metric.label(source=src).set(0)

The line you indicated is just if it found a night transit but no data. @nritsche

[nritsche]

Okay, whatever works. At the moment the analyzer does not change the metric in that specific case and it just stays at whatever it was on the last run.