parse a scene.config message

def scene_config(frames):
        """parse a scene.config message"""
        # "scene.config" <scene_id> <config>
        reader = MessageReader(frames)
        results = reader.string("command").uint32("scene_id").string("config").assert_end().get()
        if results.command != "scene.config":
            raise MessageParserError("Command is not 'scene.config'")
        return (results.scene_id, results.config)