fix display of nt-style realm\user
fix display of nt-style realm\user

We need to escape \ to get the desired result.
wheldom01/privacyidea,privacyidea/privacyidea,wheldom01/privacyidea,jh23453/privacyidea,privacyidea/privacyidea,wheldom01/privacyidea,jh23453/privacyidea,jh23453/privacyidea,jh23453/privacyidea,privacyidea/privacyidea,wheldom01/privacyidea,wheldom01/privacyidea,privacyidea/privacyidea,privacyidea/privacyidea,jh23453/privacyidea,jh23453/privacyidea,wheldom01/privacyidea,privacyidea/privacyidea