LU-3219 tests: add version check code to sanityn test 71

LU-3219 tests: add version check code to sanityn test 71

This patch adds Lustre version check codes into sanityn test
71 to make the test work with servers which do not have the
following patch:

Lustre-commit: 58444c4e9bc58e192f0bc0c163a5d51d42ba4255
Lustre-change: http://review.whamcloud.com/6127
or
Lustre-commit: 6a4ea7d154b6c016f482662463c9d2186176fee0
Lustre-change: http://review.whamcloud.com/6377

Test-Parameters: envdefinitions=SLOW=yes,ENABLE_QUOTA=yes \
clientdistro=el6 serverdistro=el6 clientarch=x86_64 \
serverarch=x86_64 serverjob=lustre-b2_1 serverbuildno=191 \
testlist=sanityn

Signed-off-by: Jian Yu <jian.yu@intel.com>
Change-Id: Ide9d42d4634f51110cb7036e43060b591ed970eb
Reviewed-on: http://review.whamcloud.com/6585
Tested-by: Hudson
Reviewed-by: Bob Glossman <bob.glossman@intel.com>
Tested-by: Maloo <whamcloud.maloo@gmail.com>
Reviewed-by: Niu Yawei <yawei.niu@intel.com>
Reviewed-by: Oleg Drokin <oleg.drokin@intel.com>