erp5_certificate_authority: Fix symbolic link of revogation file

See merge request !1789
9 jobs for master in 0 seconds (queued for 4 seconds)
Status Job ID Name Coverage
  External
passed ERP5.CodingStyleTest-Master

00:55:30

passed ERP5.PerformanceTest-Master

00:26:56

failed ERP5.UnitTest-Master

01:19:54

failed ERP5.UnitTest-Zope2

03:53:14

passed SlapOS.Eggs.UnitTest-Master.Python2

00:13:35

passed SlapOS.Eggs.UnitTest-Master.Python3

00:16:25

failed Wendelin.UnitTest-Master

00:32:25

passed SlapOS.Eggs.UnitTest-Master.Python2

00:12:42

passed SlapOS.Eggs.UnitTest-Master.Python3

00:14:02