helm: allow setting master.toml config (#4797)

k8s/charts/seaweedfs/templates/master-configmap.yaml

@@ -0,0 +1,15 @@
+{{- if .Values.master.enabled }}
+apiVersion: v1
+kind: ConfigMap
+metadata:
+  name: {{ template "seaweedfs.name" . }}-master-config
+  namespace: {{ .Release.Namespace }}
+  labels:
+    app.kubernetes.io/name: {{ template "seaweedfs.name" . }}
+    helm.sh/chart: {{ .Chart.Name }}-{{ .Chart.Version | replace "+" "_" }}
+    app.kubernetes.io/managed-by: {{ .Release.Service }}
+    app.kubernetes.io/instance: {{ .Release.Name }}
+data:
+  master.toml: |-
+    {{ .Values.master.config | nindent 4 }}
+{{- end }}