erp5_accounting: Fixup in Aged Balance Report to avoid query with empty list

that would return the whole catalog
6 jobs for master in 0 seconds
Status Job ID Name Coverage
  External
failed ERP5.CodingStyleTest-Master

01:13:49

passed ERP5.PerformanceTest-Master

00:23:20

failed ERP5.UnitTest-Master

02:44:39

failed ERP5.UnitTest-Master.Medusa

02:16:40

passed SlapOS.Eggs.UnitTest-Master.Python2

00:16:24

passed SlapOS.Eggs.UnitTest-Master.Python3

00:09:30