Update startup.sh

chown the working dir on startup
Use s6-setuidgid to start everything as the user abc with the UID:GID 1000:1000

startup.sh

@@ -1,5 +1,6 @@
 #!/bin/sh
 
 # Directly referencing these variables now because docker-compose sucks
-python3 setup.py --appname $APPNAME --username $ADMINUSER --password $PASSWORD
-gunicorn --workers 4 --threads 4 --bind 0.0.0.0:8080 wsgi:app
+chown -R abc:abc /app
+s6-setuidgid abc python3 setup.py --appname $APPNAME --username $ADMINUSER --password $PASSWORD
+s6-setuidgid abc gunicorn --workers 4 --threads 4 --bind 0.0.0.0:8080 wsgi:app