ActiveDirectory (LDAP) login with Windows user name or UPN (4) (4)

Task #8517

So far, ActiveDirectory login only worked if one logged in to the PC with the Windows user name (e.g. swisssalary\hamu). However, the so-called UPN (UserPrincipalName) is used more and more during registration (e.g. Hans.muster@swisssalary.ch). However, if UPN is used for logging in, logging into EasyRapport no longer works.