Return proper error in case of LDAP authentication
Return proper error in case of LDAP authentication

Ultrasonic has a specific option to use old-style authentication for
LDAP compatibility. But that's not the case of DSub, which relies on the
error message code.

By returning the appropriate code, the authentication works with DSub.

DocMarty84/oomusic,nicolasmartinelli/oomusic,DocMarty84/oomusic,nicolasmartinelli/oomusic