Updated piratebay.py with oldpiratebay.org urls

Thanks to 'nizzle' who was so kind to provide these changes on SickRage forums: https://sickrage.tv/forums/forum/main-category/main-forum/15133-piratebay-down-way-to-use-oldpiratebay-org?p=15276#post15276
Merge pull request #1146 from jeroenpeters1986/piratebay-url-update

Updated piratebay.py with oldpiratebay.org urls