Fix local IP address validation
    
    Previously bf9886a84393d1d1546db7e49b102e08a16a83e7 match_local has
    undesirable side effect that CheckedIPAddress object has set self._net
    from local interface.
    
    However with the recent changes, match_local is usually set to False,
    thus this side effect stops happening and default mask per address class
    is used. This causes validation error because mask on interface and mask
    used for provided IP addresses differ (reporducible only with classless
    masks).
    
    FreeIPA should compare only IP addresses with local addresses without masks
    
    https://pagure.io/freeipa/issue/4317
    
    Reviewed-By: David Kupka <dkupka@redhat.com>