[#2180] Fix ordering of piece jointe champs

app/services/pieces_justificatives_service.rb

@@ -33,7 +33,13 @@ class PiecesJustificativesService
   end
 
   def self.types_pj_as_types_de_champ(procedure)
-    order_place = procedure.types_de_champ.last&.order_place || 0
+    last_champ = procedure.types_de_champ.last
+    if last_champ.present?
+      order_place = last_champ.order_place + 1
+    else
+      order_place = 0
+    end
+
     types_de_champ = [
       TypeDeChamp.new(
         libelle: "Pièces jointes",