workaround race condition for queries over multiple series
workaround race condition for queries over multiple series

- when querying A + B, the values might intermediately result false
  values when the latest value of either A or B is still missing
- workaround by adding a small (10s) lag to queries

MartinNowak/alertd,MartinNowak/alertd,MartinNowak/alertd,MartinNowak/alertd