add validation for under trash pages

src/server/views/layout-growi/page_list.html

@@ -26,7 +26,9 @@
 
 
 {% block content_main_after %}
-  <div id="trash-page"></div>
+  {% if isTrashPage() %}
+    <div id="trash-page"></div>
+  {% endif %}
   {% if page %}
     {% include '../widget/page_attachments.html' %}
   {% endif %}