LU-9384 tests: skip 2.9 filesystem images on 2.10

LU-9384 tests: skip 2.9 filesystem images on 2.10

The 2.9 disk images upgraded to 2.10 are causing common test failures
due to small differences in space usage.  Disable testing these images
until a proper fix is available.

Test-Parameters: trivial envdefinitions=ONLY=32 testlist=conf-sanity
Signed-off-by: Andreas Dilger <andreas.dilger@intel.com>
Change-Id: I64d14ac6b079c50ee234ff886c9a80d9213ebbe5
Reviewed-on: https://review.whamcloud.com/26789
Tested-by: Jenkins
Tested-by: Maloo <hpdd-maloo@intel.com>