LU-15467 tests: fix sanity-hsm test_103a timeout issue

LU-15467 tests: fix sanity-hsm test_103a timeout issue

Add check mds version in "sanity-hsm test_103a" for interop test.
Limit the number of parralel hsm restore requests to
max_rpcs_in_flight.

Fixes: b449f3d ("LU-15145 hsm: unlock the restore layout lock for a cancel")
Test-Parameters: trivial
Test-Parameters: testlist=sanity-hsm env=ONLY=103a,ONLY_REPEAT=20
Test-Parameters: testlist=sanity-hsm
Signed-off-by: Etienne AUJAMES <etienne.aujames@cea.fr>
Change-Id: I78098042d1316cdcc9d2e25860099a0ffdba2503
Reviewed-on: https://review.whamcloud.com/46252
Tested-by: jenkins <devops@whamcloud.com>
Tested-by: Maloo <maloo@whamcloud.com>
Reviewed-by: Andreas Dilger <adilger@whamcloud.com>
Reviewed-by: Alena Nikitenko <anikitenko@ddn.com>
Reviewed-by: Oleg Drokin <green@whamcloud.com>