stack/erp5: add exiftool.

4 jobs for master in 0 seconds
Status Job ID Name Coverage
  External
passed SlapOS.SlapRunner.ResilienceTest-Master

00:30:40

failed SlapOS.SlapRunner.ResilienceTest-Master.ERP5

00:08:35

failed SlapOS.SoftwareReleases.IntegrationTest-Master.Python2

06:43:12

failed SlapOS.SoftwareReleases.IntegrationTest-Master.Python3

02:50:40