torture/drs: run repl_schema in vampire_2000_dc environment as well

torture/drs: run repl_schema in vampire_2000_dc environment as well

This will be necessary as linked attributes are handled differently in
Windows 2000.

We also only check msDS-IntId if we have a functional level of > Windows
2000, as this attribute is not present on lower domain function levels.

Signed-off-by: Bob Campbell <bobcampbell@catalyst.net.nz>
Reviewed-by: Garming Sam <garming@catalyst.net.nz>
Reviewed-by: Andrew Bartlett <abartlet@samba.org>
BUG: https://bugzilla.samba.org/show_bug.cgi?id=11139