[ticket/15687] Force supplied filename to be correct and modify route

PHPBB3-15687

phpBB/includes/message_parser.php

@@ -1719,7 +1719,7 @@ class parse_message extends bbcode_firstpass
 							$download_url = $controller_helper->route(
 								'phpbb_storage_attachment',
 								[
-									'file'		=> (int) $new_entry['attach_id'],
+									'id'		=> (int) $new_entry['attach_id'],
 									'filename'	=> $new_entry['real_filename'],
 								]
 							);