s3:winbindd: Add a sanity check for the range

s3:winbindd: Add a sanity check for the range

What we want to avoid:

$ ./bin/testparm -s | grep "idmap config"
        idmap config * : rangesize = 10000
        idmap config * : range = 10000-19999
        idmap config * : backend = autorid

$ ./bin/wbinfo --name-to-sid BUILTIN/Administrators
S-1-5-32-544 SID_ALIAS (4)

$ ./bin/wbinfo --sid-to-gid S-1-5-32-544
10000

$ ./bin/wbinfo --name-to-sid ADDOMAIN/alice
S-1-5-21-4058748110-895691256-3682847423-1107 SID_USER (1)

$ ./bin/wbinfo --sid-to-gid S-1-5-21-984165912-589366285-3903095728-1107
failed to call wbcSidToGid: WBC_ERR_DOMAIN_NOT_FOUND
Could not convert sid S-1-5-21-984165912-589366285-3903095728-1107 to gid

If only one range is configured we are either not able to map users/groups
from our primary *and* the BUILTIN domain. We need at least two ranges to also
cover the BUILTIN domain!

BUG: https://bugzilla.samba.org/show_bug.cgi?id=14967

Signed-off-by: Andreas Schneider <asn@samba.org>
Reviewed-by: Guenther Deschner <gd@samba.org>
(cherry picked from commit fe84ae5547313e482ea0eba8ddca5b38a033dc8f)