Add hack to enable multilogin.

appengine/swarming/templates/root.html

 {% extends "swarming/base.html" %}
 
 
 {% block headers %}
 <script src="/third_party/webcomponentsjs/webcomponents.min.js"></script>
 <link rel="import" href="/elements/stats-overview-build.html">
 <style>
   .highlight_section {
     background-color: #ffffee;
     border-radius: 20px;
@@ skipping 36 matching lines @@
 <div layout horizontal>
   <div>
     <div class=highlight_section>
       Swarming Server is an open source task distribution service. It is written
       in python and runs on <a
         href="https://cloud.google.com/appengine/">AppEngine</a>. It is part of
         <a href="https://github.com/luci/luci-py">LUCI</a>.
     </div>
     <p>
 
-    {% if not nickname %}
+    {% if user_type %}
+    As a {{user_type}}, you are entitled to see these pages:
+    {% else %}
     Please <a href="{{signin_link|safe}}">sign in</a> for more access.
-    {% else %}
-    As a {{user_type}}, you are entitled to see these pages:
     {% endif %}
 
     <h3>Service Status</h3>
     <ul>
       <li class="user"><a href="/stats">Usage statistics</a></li>
       <li class="user"><a href="/user/tasks">Tasks</a></li>
       <li class="privileged_user"><a href="/restricted/bots">Bots</a></li>
       <li class="admin"><a href="/restricted/ereporter2/report">Exceptions in server log</a></li>
       <li class="admin"><a href="/restricted/ereporter2/errors">Ereporter2 errors</a></li>
       <li class="admin"><a href="/restricted/mapreduce/status">Map reduce jobs</a></li>
@@ skipping 37 matching lines @@
             <button type="submit">Launch '{{job.name}}'</button>
           </form>
         </li>
       {% endfor %}
     </ul>
   </div>
   <stats-overview flex></stats-overview>
 </div>
 
 {% endblock %}