downgradedatabase: blackbox: MDB backend

downgradedatabase: blackbox: MDB backend

When Samba uses TDB as a backend store, all new database features are
toggled on/off when GUID indexing is toggled. But, GUID indexing can't
be disabled on MDB, so the other features are toggled separately.
Consequently, the downgradedatabase script behaves differently depending
on the database backend. This patch adds testing for the MDB behaviour.

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