Broken sendMediaGroup

[cmd410]

sendMediaGroup request does not work for some reason

Server returns data:
{"ok":false,"error_code":400,"description":"Bad Request: can't parse media JSON object"}

Data sent by bot:

{"chat_id": <chat_id>,
 "media": [{"media": "<link/to/image.jpg>",
            "type": "photo"},
           {"media": "<link/to/image.jpg>",
            "type": "photo"}]}

seems to be in line with documentation, still doesn't not work.

Code is in fixme_broken_send_media_group branch