erp5_crm: do not list twice a same user when ingesting an email

10 jobs for for_testrunner_3 in 0 seconds
Status Job ID Name Coverage
  External
passed ERP5.CodingStyleTest-Master

02:28:17

passed ERP5.CodingStyleTest-TestRunner3

01:34:18

failed ERP5.PerformanceTest-Master

00:35:25

failed ERP5.UnitTest-Master

02:44:03

failed ERP5.UnitTest-TestRunner3

01:49:20

passed SlapOS.Eggs.UnitTest-Master.Python2

00:14:54

passed SlapOS.Eggs.UnitTest-Master.Python3

00:21:05

failed Wendelin.UnitTest-Master

00:27:16

failed ERP5.UnitTest-TestRunner3

03:25:58

failed Wendelin.UnitTest-Master

00:54:26