erp5_trade_ja: workaround for tax number bug.

bt5/erp5_trade_ja/SkinTemplateItem/portal_skins/erp5_trade_ja/Invoice_viewAsHTML.zpt

@@ -739,7 +739,7 @@ footer {
           <tr>
             <td>
               <span>
-                0
+                
               </span>
             </td>
             <td>
@@ -760,7 +760,7 @@ footer {
           </tr>
           <tr tal:repeat='line_tax_dict python:data_dict["line_tax"]'>
             <td>
-              <span>
+              <span tal:content="python:test(line_tax_dict.get('use_type_tax'), '1', '0')">
                 1
               </span>
             </td>