fix(datanode): use with for each secret field (#77)

Author: monrax

charts/graylog/templates/config/secret/datanode.yaml

@@ -7,5 +7,9 @@ metadata:
   annotations:
     {{- include "graylog.annotations" . | nindent 4 }}
 data:
-  GRAYLOG_DATANODE_S3_CLIENT_DEFAULT_SECRET_KEY: {{ .Values.datanode.config.s3ClientDefaultSecretKey | b64enc }}
-  GRAYLOG_DATANODE_S3_CLIENT_DEFAULT_ACCESS_KEY: {{ .Values.datanode.config.s3ClientDefaultAccessKey | b64enc }}
+  {{- with .Values.datanode.config.s3ClientDefaultSecretKey }}
+  GRAYLOG_DATANODE_S3_CLIENT_DEFAULT_SECRET_KEY: {{ . | b64enc }}
+  {{- end }}
+  {{- with .Values.datanode.config.s3ClientDefaultAccessKey }}
+  GRAYLOG_DATANODE_S3_CLIENT_DEFAULT_ACCESS_KEY: {{ . | b64enc }}
+  {{- end }}