New celery beat run command for supervisor (celery#6645)

* Update extra/supervisord/celeryd.conf line 18

Adding compatibility with celery 5.0.6 which have different worker 'run' command

* Changes celery beat run command in supervisor's celerybeat.conf file
Due to new celery 5.0.5 syntax

extra/supervisord/celerybeat.conf

@@ -4,7 +4,7 @@
 
 [program:celerybeat]
 ; Set full path to celery program if using virtualenv
-command=celery beat -A myapp --schedule /var/lib/celery/beat.db --loglevel=INFO
+command=celery -A myapp beat --schedule /var/lib/celery/beat.db --loglevel=INFO
 
 ; remove the -A myapp argument if you aren't using an app instance