f0b4d48 cache_req: keep the files provider as the first domain to be searched

Authored and Committed by fidencio 5 years ago
    cache_req: keep the files provider as the first domain to be searched
    
    Currently we can't guarantee any order on which domain will the first to
    be searched. More than that, in case domain_resolution_order is set, we
    actually enforce that the first domain searched will respect the option
    set.
    
    This behaviour is not exactly the expect, as the implicit files domain
    has to be searched first in order to avoid querying for local users in
    remote domains. In order to enforce this, let's just keep the files
    domain as the first to be searched, always!
    
    Resolves:
    https://pagure.io/SSSD/sssd/issue/3768
    
    Signed-off-by: Fabiano FidĂȘncio <fidencio@redhat.com>
    Reviewed-by: Sumit Bose <sbose@redhat.com>