[systemd] Use just for celery too

systemd/.config/systemd/user/celery@.service

@@ -7,7 +7,7 @@ Wants=network-online.target
 Type=simple
 Environment=PATH=%h/.local/bin:/home/linuxbrew/.linuxbrew/bin:/usr/local/bin:/usr/bin:/bin
 EnvironmentFile=%h/.local/etc/django/%i.env
-ExecStart=/bin/bash -c 'cd "$DJANGO_PATH" && exec direnv exec "$DJANGO_PATH" celery -A "$CELERY_APP" worker'
+ExecStart=/bin/bash -c 'cd "$DJANGO_PATH" && direnv exec "$DJANGO_PATH" just celery'
 Restart=on-failure
 RestartSec=2
 StandardOutput=append:/tmp/celery.log