removing upstart script for worker

playbooks/roles/edxapp/tasks/service_variant_config.yml

-- name: edxapp | create edx-workers upstart script
-  template: >
-    src=edx-workers.conf.j2 dest=/etc/init/edx-workers.conf
-    owner=root group=root
-  when: celery_worker is defined
-
-
 - name: "create {{ item }} application config"
   template: >
     src={{ item }}.env.json.j2