LU-15098 tests: sanity-sec 27a exec commands on right node

LU-15098 tests: sanity-sec 27a exec commands on right node

In nodemap_exercise_fileset called from sanity-sec test 27a,
make sure all commands are executed on first client, as we are
testing properties of nodemaps 'default' and 'c0'.
And make sure 'default' nodemap has admin and trusted properties
set to 1, as we are carrying operations as root.

Test-Parameters: trivial
Test-Parameters: testlist=sanity-sec clientcount=2 env=ONLY=27a
Fixes: 0daeebcbdc ("LU-14797 nodemap: map project id")
Signed-off-by: Sebastien Buisson <sbuisson@ddn.com>
Change-Id: Idd9f391db60475721f3a3856b5e3bee1a18bbbca
Reviewed-on: https://review.whamcloud.com/45293
Tested-by: jenkins <devops@whamcloud.com>
Tested-by: Maloo <maloo@whamcloud.com>
Reviewed-by: Jian Yu <yujian@whamcloud.com>
Reviewed-by: Andreas Dilger <adilger@whamcloud.com>