Duplicate annotations on webservice's service

We encountered a bug where annotations we want to add to the service for webservice and workhorse are added twice.

When we set annotations in the values file like this:

gitlab:    
  webservice:
    service:
      annotations:
        annotation1: annotation-value

annotation1 will be duplicated in the template. We tracked down the cause to how annotations are added to the service here:

  annotations:
    {{- include "gitlab.serviceAnnotations" $ | nindent 4 }}
    {{- if .service.annotations -}}
    {{-   toYaml .service.annotations | nindent 4 }}
    {{- end }}

If we remove either the include statement or the if statement, the duplication stops.