title: Auth.User.None when rendering a ManyToManyField
body: <p>I am trying to render a ManyToManyField from a model that render a list of hotels with staff that belong to each hotel.</p>
  
  <p>I am trying to display in the template the users that are inside the current hotel being shown but I get an error</p>
  
  <pre><code>auth.User.None
  </code></pre>
  
  <p><strong>my template</strong> </p>
  
  <pre><code>{% for Hotel in object_list %}
           {{ Hotel.collaborateurs }}
                {% endfor %}
  </code></pre>
  
  <p><strong>My models.py</strong></p>
  
  <pre><code>class Hotel(models.Model):
  collaborateurs = models.ManyToManyField(User, verbose_name="Liste des collaborateurs autorisés")
                (....)
  </code></pre>
  
  <p>Thanks</p>
  
  <p><strong>Edit ;</strong></p>
  
  <p>I am able to rend users but I have an unesthetic code being render : .</p>
  
  <p>I would like to render only the username.</p>