LU-6126 test: skip sanity test_187a, test_187b on old MDS

LU-6126 test: skip sanity test_187a, test_187b on old MDS

Don't run sanity test_187a, test_187b in interop mode for
MDS's versions older than 2.3.0 (per file data_version
implementation was included in 2.3, LU-827).

Signed-off-by: Elena Gryaznova <elena.gryaznova@seagate.com>
Xyratex-bug-id: MRP-1826
Reviewed-by: Vladimir Saveliev <vladimir_saveliev@xyratex.com>
Change-Id: I6d42b51c769be80486c84fe436f6f3f71616e1cb
Reviewed-on: http://review.whamcloud.com/13408
Tested-by: Jenkins
Tested-by: Maloo <hpdd-maloo@intel.com>
Reviewed-by: Jian Yu <jian.yu@intel.com>
Reviewed-by: Oleg Drokin <oleg.drokin@intel.com>