LU-8793 tests: add version check to conf-sanity.sh test_99

LU-8793 tests: add version check to conf-sanity.sh test_99

This patch adds Lustre version check codes into conf-sanity.sh
test_99 to make the test interoperate with servers that do not
have the following change:

Lustre-commit: 310fd9ced4e60d83d4f93ebf45f05654eff408cb
Lustre-change: http://review.whamcloud.com/21545

Test-Parameters: trivial testlist=conf-sanity
Signed-off-by: Emoly Liu <emoly.liu@intel.com>
Change-Id: I379388427c7824c21e5c1f65ec8e362ca1b7905c
Reviewed-on: https://review.whamcloud.com/23668
Tested-by: Jenkins
Tested-by: Maloo <hpdd-maloo@intel.com>
Reviewed-by: Bob Glossman <bob.glossman@intel.com>
Reviewed-by: Jian Yu <jian.yu@intel.com>
Reviewed-by: Oleg Drokin <oleg.drokin@intel.com>