migration: Use api.env variables.
Use api.env.basedn instead of anonymously accessing LDAP to get base DN.
Use api.env.basedn instead of searching filesystem for ldapi socket.
https://fedorahosted.org/freeipa/ticket/4953
Reviewed-By: Jan Cholasta <jcholast@redhat.com>
Reviewed-By: Petr Vobornik <pvoborni@redhat.com>
Reviewed-By: Alexander Bokovoy <abokovoy@redhat.com>