Update for SD-943

Author: ASz

app/views/spree/layouts/_add_js_params.html.erb

@@ -1,5 +1,5 @@
 <%= javascript_tag do %>
-  document.addEventListener("load", function(){
+  window.addEventListener("load", function(){
     Spree.url_params["locale"] = "<%= I18n.locale %>";
   })
 <% end %>