Allow searching of user with umlaut
Allow searching of user with umlaut

In userview also search for a user given name or surname with
a german umlaut.

closes #592

wheldom01/privacyidea,wheldom01/privacyidea,privacyidea/privacyidea,jh23453/privacyidea,privacyidea/privacyidea,jh23453/privacyidea,jh23453/privacyidea,privacyidea/privacyidea,privacyidea/privacyidea,privacyidea/privacyidea,jh23453/privacyidea,wheldom01/privacyidea,wheldom01/privacyidea,jh23453/privacyidea,wheldom01/privacyidea,wheldom01/privacyidea,privacyidea/privacyidea,jh23453/privacyidea