LU-16341 tests: skip sanity-quota/test_1b for old MDS

LU-16341 tests: skip sanity-quota/test_1b for old MDS

Skip sanity-quota test_1b for old MDS missing the fix
for LU-16341 kernel NULL in qmt_site_recalc_cb.

Fixes: d965d63415 ("LU-16341 quota: fix panic in qmt_site_recalc_cb")
Test-Parameters: trivial testlist=sanity-quota env=ONLY=1b
Signed-off-by: Alex Deiter <adeiter@tintri.com>
Change-Id: I1b1bc3fdfa8f36b0c20a9a06721735c8e02c034c
Reviewed-on: https://review.whamcloud.com/c/fs/lustre-release/+/51648
Reviewed-by: Minh Diep <mdiep@whamcloud.com>
Reviewed-by: Andreas Dilger <adilger@whamcloud.com>
Reviewed-by: Oleg Drokin <green@whamcloud.com>
Tested-by: jenkins <devops@whamcloud.com>
Tested-by: Maloo <maloo@whamcloud.com>