LU-13628 tests: add sanityn test_106 to ALWAYS_EXCEPT

LU-13628 tests: add sanityn test_106 to ALWAYS_EXCEPT

sanityn test_106 fails on CentOS 8 and Ubuntu 18, and is skipped
on all other distros because of lack of support for statx.

Test-Parameters: trivial
Test-Parameters: clientdistro=el8.1 testlist=sanityn
Test-Parameters: clientdistro=ubuntu1804 testlist=sanityn
Signed-off-by: Sebastien Buisson <sbuisson@ddn.com>
Change-Id: I370585138bbd05d1e4ea8f323c74659145fe7dec
Reviewed-on: https://review.whamcloud.com/38815
Tested-by: jenkins <devops@whamcloud.com>
Reviewed-by: Alex Zhuravlev <bzzz@whamcloud.com>
Tested-by: Maloo <maloo@whamcloud.com>
Reviewed-by: Andreas Dilger <adilger@whamcloud.com>
Reviewed-by: Oleg Drokin <green@whamcloud.com>