[BUG] Await upload_media with AsyncWhatsApp throws error

[nutax]

document = await app.upload_media(f"./sample.pdf")

ERROR: Only io.IOBase, multidict and (name, file) pairs allowed, use .add_field() for passing more complex parameters, got <MultipartEncoder: {'file': ('./sample.pdf', <_io.BufferedReader name='/sample.pdf'>, 'application/pdf'), 'messaging_product': 'whatsapp', 'type': 'application/pdf'}>

[filipporomani]

Working on this!

[filipporomani]

As I found no actual way to fix this issue - the aiohttp multiwriter is just crap for this kind of stuff - I decided to keep this function syncronous and so also blocking.
Reading the files in a non-blocking way is also way complex to implement, so the function would be blocking anyways.

I'll see if I'm able to find a solution in the future, but for now I'm gonna push a fix commit for this issue that basically makes the function blocking (you still need to await it tho).

Thank you for reporting the issue!