API List of sites is not appearing when user is not a superuser

### How did you install LiveORC (docker, installer, self-deployed)?

self-deployed

### What's your browser and operating system? (Copy/paste the output of https://www.whatismybrowser.com/)

Python (api request)

### What is the problem?

https://<url>/api/site returns an empty list in case the user is not a superuser. 

### How can we reproduce this?

Try the above API request
