Enable whole thread template caching in thread list again

boards/templates/boards/all_threads.html

@@ -4,6 +4,7 b''
 {% load board %}
 {% load static %}
 {% load tz %}
+{% load cache %}
 
 {% block head %}
     <meta name="robots" content="noindex">
@@ -118,6 +119,7 b''
         {% endif %}
 
         {% for thread in threads %}
+            {% cache 500 thread thread.id thread.last_edit_time LANGUAGE_CODE TIME_ZONE %}
             <div class="thread">
                 {% post_view thread.get_opening_post thread=thread truncated=True need_open_link=True %}
                 {% if not thread.archived %}
@@ -141,6 +143,7 b''
                     {% endwith %}
                 {% endif %}
             </div>
+            {% endcache %}
         {% endfor %}
 
         {% if next_page_link %}