Omit realm parameter to validate/check if realm is empty in config

[laclaro]

Apparently it is not possible to let privacyIDEA decide about the realm to use, since the realm parameter is always sent.

If <realm></realm> is configured as empty in config.xml, I suggest to omit the realm parameter to the POST request.

By doing this, privacyIDEA will either use the default realm or determine the realm from the username by splitting.

[sbidy]

Yes that's true. I'll push that enhancement to the backlog. But the provider is currently not under "heavy" development.