Get REALM from userPrincipalName

[jroth-haj]

Currently only the NETBIOSDOMAIN is supported as realm.
Please change the code to also support the FQDN!
This is very useful with the privacyIDEA option "Use the @ sign to separate the rights amen and the realm."

Many Thanks!

[jroth-haj]

After having a look to then Code, I decided to solve this in Pull request #50

[sbidy]

Thank you - I saw your pull and the changes.
Unfortunately my test and build environment was purged. I'll try to test and build-in your changes.