sdap_idamp: Fall back to another method if sid is wrong
sss_idmap_domain_has_algorithmic_mapping can return also
IDMAP_SID_INVALID, but it does not mean that idmaping is
unavailable. We should fall back to another method of detection
(sss_idmap_domain_by_name_has_algorithmic_mapping)
and do not return false immediately.
Resolves:
https://fedorahosted.org/sssd/ticket/2172