Usage: autojpg(enabled)
This filter overrides AUTO_PNG_TO_JPG config variable.
AUTO_PNG_TO_JPG
True
http://localhost:8888/unsafe/300x300/filters:autojpg()/https%3A%2F%2Fgithub.com%2Fthumbor%2Fthumbor%2Fraw%2Fmaster%2Fexample.jpg