erp5_authentication_policy: prevent to create too much credential recovery

See merge request !1210
6 jobs for master in 0 seconds
Status Job ID Name Coverage
  External
failed ERP5.CodingStyleTest-Master

01:26:50

passed ERP5.PerformanceTest-Master

00:30:54

failed ERP5.UnitTest-Master

01:33:32

failed ERP5.UnitTest-Master.Medusa

passed SlapOS.Eggs.UnitTest-Master.Python2

01:16:18

passed SlapOS.Eggs.UnitTest-Master.Python3

00:16:12