Kill trailing whitespace in erb files

app/views/posts/index.html.erb

@@ -13,14 +13,14 @@
         <h1>Tags</h1>
         <%= @post_set.presenter.tag_list_html(self) %>
       </section>
-      
+
       <%= render "posts/partials/index/related" %>
     </aside>
 
     <section id="content">
       <menu id="post-sections">
         <li class="active"><a href="#posts" id="show-posts-link">Posts</a></li>
-        
+
         <% if @post_set.has_wiki? %>
           <li><a href="#wiki-except" id="show-wiki-excerpt-link">Wiki</a></li>
         <% end %>
@@ -30,9 +30,9 @@
       <%= render "wiki_pages/excerpt", :post_set => @post_set %>
       <%= render "posts/partials/index/posts", :post_set => @post_set %>
 
-      <%= render_rss_advertisement("short", @post_set.has_explicit?) %>   
+      <%= render_rss_advertisement("short", @post_set.has_explicit?) %>
     </section>
-    
+
     <% content_for(:page_title) do %>
       <% if @post_set.tag_string.present? %>
         <%= @post_set.humanized_tag_string %> - <%= Danbooru.config.app_name %>
@@ -42,7 +42,7 @@
     <% end %>
 
     <%= render "posts/partials/common/secondary_links" %>
-    
+
   </div>
 </div>