LU-15593 tests: fix sanity-flr/44e interop check

LU-15593 tests: fix sanity-flr/44e interop check

sanity-flr.sh test_44e was failing interop testing with 2.15 servers
because the version check was 2.14.52 when the patch didn't land
until v2_15_50-155-ga3f1c4622a. Update the interop check accordingly.

Test-Parameters: trivial testlist=sanity-flr
Test-Parameters: testlist=sanity-flr env=ONLY=44 serverversion=2.15
Fixes: a3f1c4622a ("LU-15593 mdt: Add option to disable use of SOM")
Signed-off-by: Frederick Dilger <fdilger@whamcloud.com>
Change-Id: I432078410003bea260032473729d89c9e174330f
Reviewed-on: https://review.whamcloud.com/c/fs/lustre-release/+/55845
Reviewed-by: Andreas Dilger <adilger@whamcloud.com>
Reviewed-by: Jian Yu <yujian@whamcloud.com>
Reviewed-by: Oleg Drokin <green@whamcloud.com>
Tested-by: jenkins <devops@whamcloud.com>
Tested-by: Maloo <maloo@whamcloud.com>