testBusinessTemplateTwoFileExport: Make output_encoding explicit as it should have always been.

This fixes a failure due to Zope4 now defaulting to utf-8.

product/ERP5/tests/testBusinessTemplateTwoFileExport.py

@@ -1081,7 +1081,9 @@ AAAFCAYAAACNbyblAAAAHElEQVQI12P4//8/w38GIAXDIBKE0DHxgljNBAAO
                          "content_type": "text/html",
                          "output_encoding": "iso-8859-15"}
     skin_folder._setObject(page_template_id, ZopePageTemplate(
-      page_template_id, page_template_text, page_template_kw["content_type"]))
+      page_template_id, page_template_text, page_template_kw["content_type"],
+      # When not passed, default to iso-8859-15 on Zope2 and utf-8 on Zope4
+      output_encoding=page_template_kw["output_encoding"]))
 
     self.template.edit(template_skin_id_list=[skin_folder_id+'/'+page_template_id,])