Fix (presumably) emacs26 issues re completed tasks appearing in agenda

agenda.el

@@ -4,6 +4,7 @@
 (setq org-deadline-warning-days 0)
 (setq org-agenda-skip-scheduled-if-done t)
 (setq org-agenda-skip-deadline-if-done t)
+(setq org-agenda-skip-timestamp-if-done t)
 (setq calendar-day-name-array ["de Sul" "de Lun" "de Meurth" "de Mergher"
 			       "de Yow" "de Gwener" "de Sadorn"])
 (setq calendar-day-abbrev-array ["Su" "L" "Mth" "Mr" "Y" "G" "Sa"])