LU-12982 tests: skip conf-sanity 5i for old servers

LU-12982 tests: skip conf-sanity 5i for old servers

conf-sanity tests 5i was added to lustre-master with version
2.12.54.  For all version interop testing with Lustre servers with
version less than 2.12.54 and newer clients, conf-sanity test 5i
will fail and should be skipped.

Lustre-change: https://review.whamcloud.com/36811
Lustre-commit: fee87077d83436005d6bef1c5c9673877ac4d7c1

Fixes: d1b5146eda4f (LU-12206 mdt: mdt_init0 failure handling)

Test-Parameters: trivial
Test-Parameters: serverversion=2.12.6-ddn42 serverdistro=el7.9 env=ONLY=5 testlist=conf-sanity
Test-Parameters: env=ONLY=5 testlist=conf-sanity

Signed-off-by: James Nunez <jnunez@whamcloud.com>
Change-Id: Ia493b6f80b42fbd92254150e8d40a6fbb1039635
Reviewed-by: Wei Liu <sarah@whamcloud.com>
Reviewed-by: Vikentsi Lapa <vlapa@whamcloud.com>
Reviewed-on: https://review.whamcloud.com/44497
Tested-by: jenkins <devops@whamcloud.com>
Tested-by: Maloo <maloo@whamcloud.com>
Reviewed-by: Andreas Dilger <adilger@whamcloud.com>