LU-17357 mgc: wait for sptlrpc config log

LU-17357 mgc: wait for sptlrpc config log

The sptlrpc config log is mandatory to establish connections to
targets with proper security context. So wait for its retrieval.

Add sanity-sec test_68 to exercise this, and improve test_32
for mgssec.

Lustre-change: https://review.whamcloud.com/53423
Lustre-commit: 4a3e428361a03b4bc777eddd466ba1ff8b72b51e

Signed-off-by: Sebastien Buisson <sbuisson@ddn.com>
Change-Id: I5352e926dc6a9a68db1224629c68a42b74bee8a4
Reviewed-by: Mikhail Pershin <mpershin@whamcloud.com>
Reviewed-by: Andreas Dilger <adilger@whamcloud.com>
Reviewed-on: https://review.whamcloud.com/c/ex/lustre-release/+/54160
Tested-by: jenkins <devops@whamcloud.com>
Tested-by: Maloo <maloo@whamcloud.com>