title: Url namespace not being registered for python social auth
body: <p>I have a legacy application using django 1.4.2 and python-social-auth.</p>
  
  <p>I have the app installed </p>
  
  <pre><code>INSTALLED_APPS = (
       ...
       'social.apps.django_app.default',
       ...
  )
  </code></pre>
  
  <p>The backends:</p>
  
  <pre><code>AUTHENTICATION_BACKENDS = (
      'social.backends.facebook.FacebookAppOAuth2',
      'social.backends.facebook.FacebookOAuth2',
      'social.backends.google.GoogleOAuth',
      'social.backends.google.GoogleOAuth2',
      'social.backends.google.GoogleOpenId',
      'django.contrib.auth.backends.ModelBackend',
  )
  </code></pre>
  
  <p>More settings...</p>
  
  <pre><code>SOCIAL_AUTH_FACEBOOK_ID = ''
  SOCIAL_AUTH_FACEBOOK_SECRET = ''
  
  SOCIAL_AUTH_ENABLED_BACKENDS=('facebook', 'google')
  SOCIAL_AUTH_DEFAULT_USERNAME= lambda u: slugify(u)
  </code></pre>
  
  <p>And in my root url :</p>
  
  <pre><code>urlpatterns += patterns('',
      url('', include('social.apps.django_app.urls', namespace='social'))
  </code></pre>
  
  <p>But I still get this error:</p>
  
  <pre><code>Template error:
  In template /home/matias/Proyectos/apuntes/copias/templates/login.html, error at line 9
   9 : &lt;p&gt;Ingresá con tu cuenta de &lt;a class="login facebook" href=" {% url 'social:begin' 'facebook' %} {% if request.GET.next %}?next={{ request.GET.next }}{% endif %}"&gt;Facebook&lt;/a&gt; &lt;/p&gt;
  Exception Type: NoReverseMatch at /login
  Exception Value: u"'social" is not a registered namespace
  </code></pre>
  
  <p>I don't know what's missing. As far as I can tell I have everything right.</p>
  
  <p>The quoting in the error messages worries me. But the urls.py is fine so maybe it's django formatting being funny.</p>
  
  <p>Any pointer?</p>