Airflow starting with upstart

Question

I have old version of upstart (0.6.5) and want to start airflow webserver with upstart.

  description "Airflow webserver daemon"

  start on started network-services
  stop on (deconfiguring-networking or runlevel [016])

  respawn
  respawn limit 5 30



  script
  su - airflow -c "source /home/airflow/airflow_venv/bin/activate; export AIRFLOW_HOME=/home/airflow/celery_airflow/airflow_home; airflow webserver"
  end script

This is .conf file. Command "initctl start airflow-webserver" run correctly. If I want to stop webserver with command "initctl stop airflow-webserver", it didnt stop. Process with starting pid shutdown, but in htop I see another webserver process with gunicorn workers. How can I stop webserver?