samdb: test for schemainfo update with relax control

samdb: test for schemainfo update with relax control

Currently schema info's revision field isn't incremented if relax
control is present.  This is so that no increment is done during
provision, but we need the relax control in other situations where the
increment is desired.  This patch adds a failing test to expose the
problem.

BUG: https://bugzilla.samba.org/show_bug.cgi?id=13799

Signed-off-by: Aaron Haslett <aaronhaslett@catalyst.net.nz>
Reviewed-by: Stefan Metzmacher <metze@samba.org>
Reviewed-by: Andrew Bartlett <abartlet@samba.org>
Reviewed-by: Garming Sam <garming@catalyst.net.nz>