Fix indentation

[mateuszdrab]

Issue #74

Fixed indentation which resolved helm error:

Error: UPGRADE FAILED: YAML parse error on k8s-ephemeral-storage-metrics/templates/metrics.yaml: error converting YAML to JSON: yaml: line 16: did not find expected key

Tested with values:

interval: 60
serviceMonitor:
  metricRelabelings:
    - sourceLabels: [pod_name]
      targetLabel: pod
    - sourceLabels: [pod_namespace]
      targetLabel: namespace
    # drop labels pod_.*
    - regex: "pod_(.*)"
      action: labeldrop

Deployed manifest spec:

spec:
  endpoints:
  - interval: 60s
    metricRelabelings:
    - action: replace
      sourceLabels:
      - pod_name
      targetLabel: pod
    - action: replace
      sourceLabels:
      - pod_namespace
      targetLabel: namespace
    - action: labeldrop
      regex: pod_(.*)
    path: /metrics
    port: metrics
    scheme: http
  namespaceSelector:
    matchNames:
    - kube-system
  selector:
    matchLabels:
      app.kubernetes.io/instance: k8s-ephemeral-storage-metrics
      app.kubernetes.io/name: k8s-ephemeral-storage-metrics