LU-17216 ofd: skip sanity/70a on old OSTs

LU-17216 ofd: skip sanity/70a on old OSTs

OSTs older than 2.15.59 won't have enable_health_write.
So skip the sanity/70a that requires it.

Test-Parameters: trivial
Test-Parameters: testlist=sanity clientversion=2.15 env=ONLY=70a,ONLY_REPEAT=10
Test-Parameters: testlist=sanity serverversion=2.15 env=ONLY=70a,ONLY_REPEAT=10
Fixes: e383791 ("LU-17216 ofd: make enable_health_write tunable")
Signed-off-by: Timothy Day <timday@amazon.com>
Change-Id: I320f6911e7b7064d49761a022c462b7c20f3a2e1
Reviewed-on: https://review.whamcloud.com/c/fs/lustre-release/+/53770
Tested-by: jenkins <devops@whamcloud.com>
Tested-by: Maloo <maloo@whamcloud.com>
Reviewed-by: Andreas Dilger <adilger@whamcloud.com>
Reviewed-by: Alex Deiter