`flip_x` config setting doesn't affect snake

[dasl-]

cc @LesserChance

[dasl-]

actually it does work, maybe you have the config setting in the wrong stanza. It should be like this: https://github.com/dasl-/pifi/blob/96d11bbb0bbdc6cd69a662e12b5f28c66ded62d8/sample_config.json#L37