Fix typo in ServiceMonitor port name

Author: james-choncholas

charts/docker-mailserver/templates/servicemonitor.yaml

@@ -13,7 +13,7 @@ spec:
   endpoints:
     - interval: {{ .Values.metrics.serviceMonitor.scrapeInterval }}
       path: /metrics
-      port: tcp-metrics
+      port: metrics
   namespaceSelector:
     matchNames:
       - {{ .Release.Namespace }}
@@ -22,4 +22,4 @@ spec:
       app.kubernetes.io/name: {{ template "dockermailserver.fullname" . }}
       release: "{{ .Release.Name }}"
 
-{{- end }}
+{{- end }}