LU-6319 tests: Resume parallel-grouplock testing

LU-6319 tests: Resume parallel-grouplock testing

The parallel_grouplock test from the parallel-scale test suite
was added to the ALWAYS_EXCEPT list in 2009. We need to resume
testing of parallel_grouplock.

Signed-off-by: James Nunez <james.a.nunez@intel.com>
Change-Id: I70eba62f433d280f7117aea63d7c1b56cd1fb676
Reviewed-on: https://review.whamcloud.com/19107
Tested-by: Maloo <hpdd-maloo@intel.com>
Reviewed-by: Saurabh Tandan <saurabh.tandan@intel.com>
Reviewed-by: Wei Liu <wei3.liu@intel.com>
Tested-by: Jenkins
Reviewed-by: Oleg Drokin <oleg.drokin@intel.com>