LU-5641 tests: ensure user daemon is in group bin

sanity test_103a assumes user daemon is a member of group bin.
This addition makes that so even in el7 where it's
not true by default.

Test-Parameters: clientdistro=el7 mdsfilesystemtype=ldiskfs mdtfilesystemtype=ldiskfs ostfilesystemtype=ldiskfs
Signed-off-by: Bob Glossman <bob.glossman@intel.com>
Change-Id: I180479e80d4da5f1bfec98c25676feaae85c29d7
Reviewed-on: http://review.whamcloud.com/12044
Reviewed-by: Andreas Dilger <andreas.dilger@intel.com>
Tested-by: Jenkins
Tested-by: Maloo <hpdd-maloo@intel.com>
Reviewed-by: Jian Yu <jian.yu@intel.com>