erp5_mrp_quality_assurance: not need to set value if vin is also None

bt5/erp5_mrp_quality_assurance/SkinTemplateItem/portal_skins/erp5_mrp_quality_assurance/DeliveryLine_checkQualityAssuranceElement.py

@@ -84,7 +84,7 @@ if portal_type == "Traceability":
     return []
   else:
     assurance_document = context.getAggregateValue(portal_type=portal_type)
-    if not assurance_document.getAggregate(portal_type="VIN"):
+    if (not assurance_document.getAggregate(portal_type="VIN")) and vin:
       assurance_document.setAggregateValue(vin, portal_type="VIN")
 
 
@@ -107,7 +107,7 @@ else:
     assurance_document.plan()
   else:
     assurance_document = context.getAggregateValue(portal_type=portal_type)
-    if not assurance_document.getAggregate(portal_type="VIN"):
+    if (not assurance_document.getAggregate(portal_type="VIN")) and vin:
       assurance_document.setAggregateValue(vin, portal_type="VIN")
 
 return []