Add support for shool-ID

[natrius]

Version: 2.0.3 (via F-Droid)
Android: 8.1.0 (LineageOS)
Cellphone: OnePlus 3

In my school anonymous login combined with school-ID is provided. I actually don't know the server name itself anymore and unfortunately i can not use the app :(

[Perflyst]

For the server you can use the domain where you log in with webuntis (*.webuntis.com). Anonymous login? As far as I know you need a username. Password is optional. Correct me if I am wrong.

[natrius]

You are wrong.
In my school (evening) we tend to use just anonymous because if we log in, we don't see all the classes we have to take and thats annoying.
I found the new webuntis link (school changed it) and now it works with the anonym user.

Still, School-ID, why not if its available.