[telegraf-ds] pods don't get run on unschedulable masters

[yellowpattern]

If there are unschedulable nodes in the cluster (e.g. masters) then the pod won't run there, leaving an element of the cluster unable to be monitored for metrics.

This is required:

spec:
...
  template:
...
    spec:
...
      tolerations:
      - key: node-role.kubernetes.io/master
        effect: NoSchedule