Remove useless global variable.

git-svn-id: https://svn.erp5.org/repos/public/erp5/trunk@3713 20353a03-c40f-0410-a6d1-a30d3c3de9de

product/ERP5/Document/Invoice.py

@@ -39,9 +39,6 @@ class Invoice(AccountingTransaction):
     isPortalContent = 1
     isRADContent = 1
 
-    # Global variables
-    _transaction_line_portal_type = 'Sale Invoice Transaction Line'
-    
     # Declarative security
     security = ClassSecurityInfo()
     security.declareObjectProtected(Permissions.View)