runUnitTest: Set `skip-ownership-checking true` as we already do for a normal...

runUnitTest: Set `skip-ownership-checking true` as we already do for a normal instance through zope.conf.

Related to 58c9f7c3c688854958592590dd396929b5a0c8d4 in slapos.git.
5 jobs for arnau in 0 seconds
Status Job ID Name Coverage
  External
passed ERP5.CodingStyleTest-Master

01:04:02

passed ERP5.PerformanceTest-Master

passed ERP5.UnitTest-Master

passed SlapOS.Eggs.UnitTest-Master.Python2

00:26:40

failed SlapOS.Eggs.UnitTest-Master.Python3

00:36:40