Pipeline metrics tab shows sometimes "No data points." also when data are returned from the API

Description of problem:
Sometimes, one of the n API calls on the dashboard fails. In that case, non of the dashboard metrics are shown.

Version-Release number of selected component (if applicable):
4.14, might happen also on older versions

How reproducible:
Sometimes

Steps to Reproduce:

1. Start a pod, create some load
2. Open the metrics
3. Sometimes not all dashboards are shown

Actual results:
Missing metrics

Expected results:
Other metrics should be shown also if another metric are failing or have no data

Additional info: