create_script_tag() is malfunctioning

[phillijw]

I'm running into an issue with the following code. You can see that it's inserting an 0x02 and 0x08 where it shouldn't (see the right side of the diff). The left side is the correct output.

custom_payload = FLVObject()
custom_payload["audioBandwidth"] = struct.pack(">d", 64000.0)
custom_payload["audioChannels"] = struct.pack(">d", 1.0)
custom_payload["audioFrequency"] = struct.pack(">d", 48000.0)
custom_payload["channelId"] = struct.pack(">d", 0.0)
payload = create_script_tag('onMetaData', custom_payload, 0)

I think this is the code inserting it: https://github.com/wulczer/flvlib/blob/08967851f106158abe1115698c5cae285fed42d9/lib/flvlib/tags.py#L209