Fixed #17680 - Clarified when logging is configured.

docs/topics/logging.txt

@@ -218,10 +218,11 @@ handlers, filters and formatters that you want in your logging setup,
 and the log levels and other properties that you want those components
 to have.
 
-Logging is configured immediately after settings have been loaded.
-Since the loading of settings is one of the first things that Django
-does, you can be certain that loggers are always ready for use in your
-project code.
+Logging is configured as soon as settings have been loaded
+(either manually using :func:`~django.conf.settings.configure` or when at least
+one setting is accessed). Since the loading of settings is one of the first
+things that Django does, you can be certain that loggers are always ready for
+use in your project code.
 
 .. _dictConfig format: http://docs.python.org/library/logging.config.html#configuration-dictionary-schema