fix an issue in selecting '(None)' in workflow interaction property dialog.

product/ERP5/Interaction.py

@@ -149,6 +149,8 @@ class InteractionDefinition (SimpleItem):
           activate_script_name = ()
         if 'None' in script_name:
           script_name = ()
+        if 'None' in before_commit_script_name:
+          before_commit_script_name = ()
         self.portal_type_filter = portal_type_filter
         self.portal_type_group_filter = portal_type_group_filter
         self.title = str(title)

product/ERP5/dtml/interaction_properties.dtml

@@ -118,7 +118,7 @@
 <th align="left">Activities (later)</th>
 <td>
 <select name="activate_script_name:list" multiple size="5">
-<option value="">(None)</option>
+<option value="None">(None)</option>
 <dtml-in getAvailableScriptIds sort>
  <dtml-let selected="_['sequence-item'] in activate_script_name and 'selected' or ' '">
   <option value="&dtml-sequence-item;" &dtml-selected;>&dtml-sequence-item;</option>