Remove display of journalist username from replies in source interface

In 413e887 in #1534 we added the
display of journalist usernames in replies shown to sources in order
to improve source UX. However, we have decided that this is a change we
want to push until post-0.4, so we are going to change this back for now..

securedrop/source_templates/lookup.html

@@ -78,7 +78,7 @@ <h2 class="headline">Get Replies</h2>
               </p>
           </div>
         </form>
-        <blockquote><h5>From: {{ reply.journalist.username|title }}</h5> {{ reply.decrypted | nl2br }}</blockquote>
+        <blockquote>{{ reply.decrypted | nl2br }}</blockquote>
         <div class="clearfix"></div>
       </div>
     {% endfor %}