Kill trailing whitespace in erb files

app/views/dmails/show.html.erb

@@ -3,13 +3,13 @@
     <div class="dmail">
       <h1>Show Message</h1>
       <h2><%= @dmail.title %></h2>
-      
+
       <ul style="margin-bottom: 1em;">
         <li><strong>Sender</strong>: <%= link_to @dmail.from_name, user_path(@dmail.from_id) %></li>
         <li><strong>Recipient</strong>: <%= link_to @dmail.to_name, user_path(@dmail.to_id) %></li>
         <li><strong>Date</strong>: <%= compact_time(@dmail.created_at) %></li>
       </ul>
-      
+
       <h3>Body</h3>
       <div class="prose">
         <%= format_text(@dmail.body) %>
@@ -18,7 +18,7 @@
       <p>
         <%= link_to "Respond", new_dmail_path(:respond_to_id => @dmail) %>
         | <%= link_to "Forward", new_dmail_path(:respond_to_id => @dmail, :forward => true) %>
-      </p>      
+      </p>
     </div>
   </div>
 </div>