[ticket/12557] Fix doc block errors found by Sami pt1

PHPBB3-12557

phpBB/includes/functions_module.php

@@ -542,6 +542,8 @@ class p_master
 	* This method loads a given module, passing it the relevant id and mode.
 	*
 	* @param string $mode mode, as passed through to the module
+	* @param string|false $module_url If supplied, we use this module url
+	* @param bool $execute_module If true, at the end we execute the main method for the new instance
 	*/
 	function load_active($mode = false, $module_url = false, $execute_module = true)
 	{