Move also the comment from the helper function to core/Config.php

system/core/Config.php

@@ -327,6 +327,8 @@ class CI_Config {
 	 *
 	 * Returns local_url [. uri_string]
 	 * 
+	 * If local_url is not defined return base_url instead.
+	 *
 	 * @uses	CI_Config::_uri_string()
 	 *
 	 * @param	string|string[]	$uri	URI string or an array of segments

system/helpers/url_helper.php

@@ -97,8 +97,6 @@ if ( ! function_exists('local_url'))
 	 * within e.g. the docker container to the base_url use this url
 	 * for cron jobs.
 	 * 
-	 * If local_url is not defined return base_url instead.
-	 * 
 	 * @param	string	$uri
 	 * @param	string	$protocol
 	 * @return	string