erp5_base: Update comment

  Since the test() method was fixed the comment became irrelevant

bt5/erp5_base/DocumentTemplateItem/portal_components/document.erp5.SplitMovementGroup.py

@@ -33,10 +33,6 @@ class SplitMovementGroup(MovementGroup):
   This movement group is used to split all the movements that are aggregated
   by the Simulation Select Method.
 
-  XXX-Tatuya: However this test() method returns True, so the aggregated
-  movements can be inserted into existing Delivery/Line/Cell that are aggregated
-  by the Delivery Select Method. What use case this is applied for?
-
   * Reference:
   http://www.erp5.org/HowToConfigureMovementGroup