Disable the admin of "Site"

[Thomas Lionel Smets]

The admin console always displays the admin of "Site" page while this should be hidden for the people on a specific site (they should not be aware of the fact that there are multiple sites) !

When I add the admin.py the following line
```
admin.site.unregister(Site)
```

The (debug) server crashes with the following trace :
```
INFO autoreload P86005 T140161586511872 Watching for file changes with StatReloader
Exception in thread django-main-thread:
Traceback (most recent call last):
  File "/usr/lib/python3.10/threading.py", line 1016, in _bootstrap_inner
    self.run()
  File "/usr/lib/python3.10/threading.py", line 953, in run
    self._target(*self._args, **self._kwargs)
  File "/home/aaaaaazzzzzz/Documents/work/Projects/UseSiteAndHistoryFrameworkTogether/venv/lib/python3.10/site-packages/django/utils/autoreload.py", line 64, in wrapper
    fn(*args, **kwargs)
  File "/home/aaaaaazzzzzz/Documents/work/Projects/UseSiteAndHistoryFrameworkTogether/venv/lib/python3.10/site-packages/django/core/management/commands/runserver.py", line 125, in inner_run
    autoreload.raise_last_exception()
  File "/home/aaaaaazzzzzz/Documents/work/Projects/UseSiteAndHistoryFrameworkTogether/venv/lib/python3.10/site-packages/django/utils/autoreload.py", line 87, in raise_last_exception
    raise _exception[1]
  File "/home/aaaaaazzzzzz/Documents/work/Projects/UseSiteAndHistoryFrameworkTogether/venv/lib/python3.10/site-packages/django/core/management/__init__.py", line 394, in execute
    autoreload.check_errors(django.setup)()
  File "/home/aaaaaazzzzzz/Documents/work/Projects/UseSiteAndHistoryFrameworkTogether/venv/lib/python3.10/site-packages/django/utils/autoreload.py", line 64, in wrapper
    fn(*args, **kwargs)
  File "/home/aaaaaazzzzzz/Documents/work/Projects/UseSiteAndHistoryFrameworkTogether/venv/lib/python3.10/site-packages/django/__init__.py", line 24, in setup
    apps.populate(settings.INSTALLED_APPS)
  File "/home/aaaaaazzzzzz/Documents/work/Projects/UseSiteAndHistoryFrameworkTogether/venv/lib/python3.10/site-packages/django/apps/registry.py", line 124, in populate
    app_config.ready()
  File "/home/aaaaaazzzzzz/Documents/work/Projects/UseSiteAndHistoryFrameworkTogether/venv/lib/python3.10/site-packages/django/contrib/admin/apps.py", line 27, in ready
    self.module.autodiscover()
  File "/home/aaaaaazzzzzz/Documents/work/Projects/UseSiteAndHistoryFrameworkTogether/venv/lib/python3.10/site-packages/django/contrib/admin/__init__.py", line 50, in autodiscover
    autodiscover_modules("admin", register_to=site)
  File "/home/aaaaaazzzzzz/Documents/work/Projects/UseSiteAndHistoryFrameworkTogether/venv/lib/python3.10/site-packages/django/utils/module_loading.py", line 58, in autodiscover_modules
    import_module("%s.%s" % (app_config.name, module_to_search))
  File "/usr/lib/python3.10/importlib/__init__.py", line 126, in import_module
    return _bootstrap._gcd_import(name[level:], package, level)
  File "<frozen importlib._bootstrap>", line 1050, in _gcd_import
  File "<frozen importlib._bootstrap>", line 1027, in _find_and_load
  File "<frozen importlib._bootstrap>", line 1006, in _find_and_load_unlocked
  File "<frozen importlib._bootstrap>", line 688, in _load_unlocked
  File "<frozen importlib._bootstrap_external>", line 883, in exec_module
  File "<frozen importlib._bootstrap>", line 241, in _call_with_frames_removed
  File "/home/aaaaaazzzzzz/Documents/work/Projects/UseSiteAndHistoryFrameworkTogether/UseSiteAndHistoryFrameworkTogether/UseSiteAndHistoryFrameworkTogether/ContactManagementUseSiteAndHistory/admin.py", line 71, in <module>
    admin.site.unregister(Site)
  File "/home/aaaaaazzzzzz/Documents/work/Projects/UseSiteAndHistoryFrameworkTogether/venv/lib/python3.10/site-packages/django/contrib/admin/sites.py", line 161, in unregister
    raise NotRegistered("The model %s is not registered" % model.__name__)
django.contrib.admin.sites.NotRegistered: The model Site is not registered
```

How can I fix this ?

\T,

[Ryan Nowakowski]

If you're looking to restrict some admin users' access to the Site admin, consider creating a Django auth group for those users that excludes Site permissions.