Fix Prometheus Kubernetes SD config

There is an issue with the current scrape config for Prometheus. The line regex: __meta_kubernetes_node_label_(.+) needs to be indented.

    relabel_configs:
    - action: labelmap
    regex: __meta_kubernetes_node_label_(.+)
    metric_relabel_configs:
    - source_labels: [pod_name]
      target_label: environment
      regex: (.+)-.+-.+