Generate only one movement.

This is good enough to generate only one movement per run for given period.

Otherwise this method could generate milions of movements.

product/ERP5/Document/SubscriptionItem.py

@@ -315,6 +315,7 @@ class SubscriptionItem(Item, CompositionMixin, MovementGeneratorMixin, Periodici
           result.append(generated_movement)
           current_date = next_date
           id_index += 1
+          break
 
     return result