problem with deviantart literature

[edn8]

If literature is limited to Deviantart members, then the downloader saves an html document containing the "Please login to view this content."-message. This happens both with the default and with a custom login config. Non-literature types with the login requirement don't seem to have this issue.

The problem should be reproducible when trying to download the following:
https://www.deviantart.com/dragonblade318/art/Lynn-Bio-347088856

The download works properly when additionally passing public=False to the _call function in deviantart.py#L907, but only if I use custom API credentials. Maybe it would even be a good idea to set the _call function's default value of public to False to use the private access token whenever possible.