fix: prevent overzealous whitespace removal (#509)

Too much whitespace is removed here; if `.type` is `LoadBalancer` then
`type` and `externalTrafficPolicy` end up on the same line producing
invalid YAML. Removing the last dash means a newline will be inserted
between the entries as expected.

Resolves #508

Signed-off-by: Martin Rowe <martin.p.rowe@gmail.com>

Author: cyanidium

charts/mailu/templates/front/service-external.yaml

@@ -21,7 +21,7 @@ spec:
     app.kubernetes.io/component: front
 {{- with .Values.front.externalService }}
   type: {{ .type | default "ClusterIP" }}
-  {{- if ne .type "ClusterIP" -}}
+  {{- if ne .type "ClusterIP" }}
   externalTrafficPolicy: {{ .externalTrafficPolicy | default "Local" }}
   {{- end }}
   {{- if .loadBalancerIP }}