Verify new config - Add option to make use of SSO

[tuxmea]

SAML implementation?
Check possible options.

[tuxmea]

If LDAP and SAML are diabled: only local login shows up on webpage.

If LDAP is configured: the website shows local and ldap login
If SAML is configured: the website shows local and SAML

If SAML and LDAP are configured: ???

[tuxmea]

Implemented, needs verification.
Closing for now.