Fixed #30057 -- Fixed diffsettings ignoring custom configured settings.

Regression in 49b67937.

django/core/management/commands/diffsettings.py

 from django.core.management.base import BaseCommand
 
 
-def module_to_dict(module, omittable=lambda k: k.startswith('_')):
+def module_to_dict(module, omittable=lambda k: k.startswith('_') or not k.isupper()):
     """Convert a module namespace to a Python dictionary."""
-    return {k: repr(v) for k, v in module.__dict__.items() if not omittable(k)}
+    return {k: repr(getattr(module, k)) for k in dir(module) if not omittable(k)}
 
 
 class Command(BaseCommand):

tests/admin_scripts/configured_settings_manage.py

@@ -5,5 +5,5 @@ from django.conf import settings
 from django.core.management import execute_from_command_line
 
 if __name__ == '__main__':
-    settings.configure(DEBUG=True)
+    settings.configure(DEBUG=True, CUSTOM=1)
     execute_from_command_line(sys.argv)

tests/admin_scripts/tests.py

@@ -2236,7 +2236,7 @@ class DiffSettings(AdminScriptTestCase):
     def test_settings_configured(self):
         out, err = self.run_manage(['diffsettings'], configured_settings=True)
         self.assertNoOutput(err)
-        self.assertOutput(out, 'DEBUG = True')
+        self.assertOutput(out, 'CUSTOM = 1  ###\nDEBUG = True')
 
     def test_all(self):
         """The all option also shows settings with the default value."""