Should not remove slash after language prefix

I have a multilingual drupal site with English home page at http://www.domain.com/en/ and Chinese homepage at http://www.domain.com/cn/
The reason that the slash is add at end is that all the links in that language are relative to the language folder (eg. /cn/ ) instead of the root.
Default drupal is happy with or without the slash after the language prefix.

But when globalredirect is enabled, it will remove the end slash after the language prefix regardless if the 'deslash' option is set or not.

http://www.domain.com/cn/ --> http://www.domain.com/cn

This will cause all the links in Chinese home page relative to the root. ( I know I can specify a absolute link, but I am lazy )

I have made an one line patch that fixes the problem. Please test.