supervisor-xqueue: Run the xqueue processes as `common_web_user`

supervisord as well as all the processes it controls are run as
`{{ common_web_user }}`. This allows us to connect to it as that
user which allows us to manage the processes as www-data, instead
of root.

playbooks/roles/xqueue/tasks/deploy.yml

@@ -32,7 +32,7 @@
 - name: "xqueue | writing supervisor scripts - xqueue, xqueue consumer"
   template: >
     src={{ item }}.conf.j2 dest={{ supervisor_cfg_dir }}/{{ item }}.conf
-    owner={{ supervisor_user }} group={{ xqueue_user }} mode=0644
+    owner={{ supervisor_user }} group={{ common_web_user }} mode=0644
   with_items: ['xqueue', 'xqueue_consumer']
   notify: supervisor | restart supervisor
   tags:

playbooks/roles/xqueue/templates/xqueue.conf.j2

@@ -6,7 +6,7 @@ command={{ xqueue_venv_dir }}/bin/gunicorn --preload -b {{ xqueue_gunicorn_host
 command={{ xqueue_venv_dir }}/bin/gunicorn --preload -b {{ xqueue_gunicorn_host }}:{{ xqueue_gunicorn_port }} -w 2 --timeout=300 --pythonpath={{ xqueue_code_dir }} xqueue.wsgi
 {% endif %}
 
-user={{ xqueue_user }}
+user={{ common_web_user }}
 directory={{ xqueue_code_dir }}
 
 environment=PID=/var/tmp/xqueue.pid,PORT={{ xqueue_gunicorn_port }},ADDRESS={{ xqueue_gunicorn_host }},LANG={{ XQUEUE_LANG }},DJANGO_SETTINGS_MODULE=xqueue.aws_settings,SERVICE_VARIANT="xqueue"

playbooks/roles/xqueue/templates/xqueue_consumer.conf.j2

@@ -2,7 +2,7 @@
 
 command={{xqueue_venv_dir}}/bin/django-admin.py run_consumer --pythonpath={{xqueue_code_dir}} --settings=xqueue.aws_settings $WORKERS_PER_QUEUE
 
-user={{ xqueue_user }}
+user={{ common_web_user }}
 directory={{ xqueue_code_dir }}
 
 environment=LANG={{ XQUEUE_LANG }},WORKERS_PER_QUEUE={{xqueue_env_config.XQUEUE_WORKERS_PER_QUEUE}},SERVICE_VARIANT="xqueue"