CMFActivity: do not bypass the max_retry parameter for activities that timeout

See merge request !1880
5 jobs for master in 0 seconds
Status Job ID Name Coverage
  External
passed ERP5.CodingStyleTest-Master

00:53:44

failed ERP5.UnitTest-Master

01:49:37

passed SlapOS.Eggs.UnitTest-Master.Python2

00:15:21

passed SlapOS.Eggs.UnitTest-Master.Python3

00:16:14

passed Wendelin.UnitTest-Master

00:49:47