Fixed settings docs to match list/tuple changes in #24149.

docs/topics/settings.txt

@@ -166,8 +166,8 @@ Django apps. Just follow these conventions:
 * Setting names are in all uppercase.
 * Don't reinvent an already-existing setting.
 
-For settings that are sequences, Django itself uses tuples, rather than lists,
-but this is only a convention.
+For settings that are sequences, Django itself uses lists, but this is only
+a convention.
 
 .. _settings-without-django-settings-module: