Helm Chart: Fix schema of logstash default values (#3004)

* Fix schema of logstash default values

* Bump helm chart version

production/helm/loki-stack/Chart.yaml

@@ -1,6 +1,6 @@
 apiVersion: "v1"
 name: loki-stack
-version: 2.1.0
+version: 2.1.1
 appVersion: v2.0.0
 kubeVersion: "^1.10.0-0"
 description: "Loki: like Prometheus, but for logs."

production/helm/loki-stack/values.yaml

@@ -38,9 +38,8 @@ filebeat:
 
 logstash:
   enabled: false
-  image:
+  image: grafana/logstash-output-loki
-    repository: grafana/logstash-output-loki
+  imageTag: 1.0.1
-    tag: 1.0.1
   filters:
     main: |-
       filter {