LU-6920 test: add some slack to jobstats expiry in test_205

LU-6920 test: add some slack to jobstats expiry in test_205

Add a tiny fudge factor to the time allowed for jobstats
to expire before checking on them.

Signed-off-by: Bob Glossman <bob.glossman@intel.com>
Change-Id: Iff2c70e2522b0da0e9c2080cadde49b96a9af60a
Reviewed-on: http://review.whamcloud.com/16753
Reviewed-by: John L. Hammond <john.hammond@intel.com>
Tested-by: Jenkins
Tested-by: Maloo <hpdd-maloo@intel.com>
Reviewed-by: Minh Diep <minh.diep@intel.com>
Reviewed-by: Jian Yu <jian.yu@intel.com>
Reviewed-by: Oleg Drokin <oleg.drokin@intel.com>