create_db is requiring an additional argument for IPA version 4.4.4 still.

The subject base generated in discovery is only a guess and might have been
changed by the admin at installation process. Therefore it is needed to
get this from the server.

subject_base has been added as a new return value.

Use subject base form ipaapi in roles/ipaclient/tasks/install.yml instead of
guessed value from ipadiscovery.