deb init script doesn't use appropriate functions from init-functions

[kylejohnson]

I'll submit a PR for this shortly

[stale]

In an effort to focus on bugs and issues that impact currently supported versions of Rundeck, we have elected to notify GitHub issue creators if their issue is classified as stale and close the issue. An issue is identified as stale when there have been no new comments, responses or other activity within the last 12 months. If a closed issue is still present please feel free to open a new Issue against the current version and we will review it. If you are an enterprise customer, please contact your Rundeck Support to assist in your request.
Thank you, The Rundeck Team