Does this Plugin need to set a UserPrincipal?

[martinhaase]

When combining this plugin with SPNEGO login, the latter spits out a principal. This plugin is able to use this principal, but adds another with the same user name. This seems useless and actually blocks using the https://wiki.shibboleth.net/confluence/display/IDP30/SimplePostLoginC14NConfiguration needed for SPNEGO, since we have now two independent principals. Disabling the extra principal seemed to do the trick:

src/main/java/ca/ab/concordia/privacyIDEAtfa/TokenValidator.java:```

// do not let 2FA set username
// subject.getPrincipals().add(new UsernamePrincipal(username));