Allow passing only qburl in parameters

[StereotypicalCat]

Type: Feature Request

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Summary

qBittorrent has an option to allow urls from localhost without authentication. However when auth = none, flood requires both url and username + password to launch.

Idea of implementation

If only url is supplied, try to connect to torrent client without user and pass, and if it doesn't work, throw an exception saying the program needs a user and password.
Alternatively, adding another parameter, along the lines of backend-auth = none

[jesec]

Does qBittorrent fail if (wrong) username or password was provided when its auth is disabled? If it doesn't, it might be simpler to just use random username/password.