move bottom_content article content to Redis (#4927)

.rubocop_todo.yml

@@ -61,6 +61,7 @@ Rails/OutputSafety:
     - 'app/models/message.rb'
     - 'app/views/articles/_actions.html.erb'
     - 'app/views/articles/feed.rss.builder'
+    - 'app/views/articles/show.html.erb'
 
 # Offense count: 25
 # Cop supports --auto-correct.

app/views/articles/show.html.erb

@@ -199,7 +199,7 @@
     <%= render "articles/full_comment_area" %>
   </div>
 
-  <% cache("article-bottom-content-#{@article.id}", expires_in: 18.hours) do %>
+  <% RedisRailsCache.fetch("article-bottom-content-#{@article.id}", expires_in: 18.hours) do %>
     <% @classic_article = Suggester::Articles::Classic.new(@article, not_ids: [@article.id]).get.first %>
     <% if @classic_article %>
       <%= render "additional_content_boxes/article_box",