[BUG] Amending Analysts permissions

[dynek]

Describe the bug
The web interface allows modifying the "Analysts" group permissions but they are overridden whenever Iris starts:
https://github.com/dfir-iris/iris-web/blob/master/source/app/post_init.py#L999-L1007

Is this done on purpose?
I haven't found anywhere in the documentation where this is mentioned, and I wonder why the web ui allows changing this if's always reverted.

To Reproduce
Steps to reproduce the behavior:

1. Go to Advanced -> Access control
2. Click on 'Analysts'
3. Modify permissions, e.g. add one
4. Restart Iris
5. Go to Advanced -> Access control
6. Click on 'Analysts'
7. Check permissions, they are back to defaults