accounting_l10n_fr_pca: fix "add new accounts from 2018"

The category titles were missing

/reviewed-on !1065
5 jobs for master in 0 seconds
Status Job ID Name Coverage
  External
passed ERP5.CodingStyleTest-Master

01:15:22

passed ERP5.PerformanceTest-Master

00:31:59

failed ERP5.UnitTest-Master

01:40:50

passed SlapOS.Eggs.UnitTest-Master.Python2

00:22:17

passed SlapOS.Eggs.UnitTest-Master.Python3

00:22:10