Fix wiki pages like this returning 406 errors: * https://danbooru.donmai.us/wiki_pages/rnd.jpg Caused by Rails parsing the .jpg part as a file extension and trying to return a JPEG in response. This happens deep in Rails' MIME negotiation code, so it's hard to override. The fix is to pass `format: false` in the route to disable all special handling of file extensions by Rails, and then handle it ourselves in the controller. Ugly. This only affected two tags: `rnd.jpg` and `haru.jpg`.