Payment: small bug in specifying translatable texts

The payment module does not specify the title and description of the menu-item E-Commerce Settings -> Payment as translatable text.

Attached patch solves this issue for the 5.x-3.x-dev branch. I tested the patch on Apache 2.2.4/PHP 5.2.3 on Ubuntu Desktop 7.10 Gutsy Gibbon. Because this is quite small and understandable patch i don't expect any problems to arise on other platforms, but it might be a good idea to test it on other platforms anyways.

So, please review. Thank you.