fix: fix templating of the metricRelabelings parameter (#615)

Co-authored-by: Katlinsky, Ilya <i.katlinsky@itransition.com>
diff --git a/charts/apisix-ingress-controller/templates/servicemonitor.yaml b/charts/apisix-ingress-controller/templates/servicemonitor.yaml
index f8dd9dc..7f37908 100644
--- a/charts/apisix-ingress-controller/templates/servicemonitor.yaml
+++ b/charts/apisix-ingress-controller/templates/servicemonitor.yaml
@@ -35,7 +35,9 @@
     {{- if .Values.serviceMonitor.interval }}
     interval: {{ .Values.serviceMonitor.interval }}
     {{- end }}
-    metricRelabelings: {{ .Values.serviceMonitor.metricRelabelings }}
+    {{- with .Values.serviceMonitor.metricRelabelings }}
+    metricRelabelings: {{ toYaml . | nindent 6 }}
+    {{- end }}
   namespaceSelector:
     matchNames:
     - {{ template "apisix-ingress-controller.namespace" . }}
diff --git a/charts/apisix/templates/service-monitor.yaml b/charts/apisix/templates/service-monitor.yaml
index 87f7ede..bda6a1d 100644
--- a/charts/apisix/templates/service-monitor.yaml
+++ b/charts/apisix/templates/service-monitor.yaml
@@ -41,5 +41,7 @@
     targetPort: prometheus
     path: {{ .Values.serviceMonitor.path }}
     interval: {{ .Values.serviceMonitor.interval }}
-    metricRelabelings: {{ .Values.serviceMonitor.metricRelabelings }}
+    {{- with .Values.serviceMonitor.metricRelabelings }}
+    metricRelabelings: {{ toYaml . | nindent 6 }}
+    {{- end }}
 {{- end }}