s3:idmap:autorid prevent fatal configuration changes

s3:idmap:autorid prevent fatal configuration changes

as the autorid module relies on a stable minimum uid/gid value
and rangesize, it now saves the values used at first successful start
and refuses to work if these values get changed in smb.conf later.
Changing the values after the first mapping was done will result
in unpredictable behaviour.
Another check covers the maximum uid value. If this gets decreased
later and domain range mappings already exist that would result
in uid values higher than the new uid value, initialization will
be aborted
(cherry picked from commit 8283cdbb1f28517d3e25a958aede0e5a31131f90)