Use defined attribute kerberos logins instead the virtual one
Use defined attribute kerberos logins instead the virtual one

- use defined attribute kerberos logins, because in virtual attribute
  there can be some other not supported logins for this service

CESNET/perun-services,CESNET/perun-services,sustr4/perun-services,frhrdina/perun-services,frhrdina/perun-services,zlamalp/perun-services,stavamichal/perun-services,frhrdina/perun-services,CESNET/perun-services,sustr4/perun-services,stavamichal/perun-services,zlamalp/perun-services,zlamalp/perun-services,stavamichal/perun-services,sustr4/perun-services,sustr4/perun-services,stavamichal/perun-services,CESNET/perun-services,zlamalp/perun-services,frhrdina/perun-services