title: Django admin - filter in get_queryset not working
body: <p>I have this two models</p>
  
  <pre><code>class Invitacion(models.Model):
     id = models.UUIDField(primary_key=True, default=uuid.uuid4, editable=False)
     host = models.ForeignKey(settings.AUTH_USER_MODEL, on_delete=models.CASCADE)
     name = models.CharField(max_length=256, verbose_name="Nombre Invitacion")
  
  
  class Invitado(models.Model):
     id = models.UUIDField(primary_key=True, default=uuid.uuid4, editable=False)
     invitacion = models.ForeignKey(Invitacion, on_delete=models.CASCADE)
     name = models.CharField(max_length=50)
   ...
  </code></pre>
  
  <p>And registered those in the admin with </p>
  
  <pre><code>admin.site.register(Invitacion)
  
  @admin.register(Invitado)
  class InvitadoAdmin(admin.ModelAdmin):
      def get_queryset(self, request):
          if request.user.is_superuser:
              return Invitado.objects.all()
          return Invitado.objects.filter(invitacion__host=request.user)
  </code></pre>
  
  <p>However this filter does not work(it returns an empty queryset):</p>
  
  <pre><code>return Invitado.objects.filter(invitacion__host=request.user)
  </code></pre>
  
  <p>If I filter on the shell it works but not on the admin.
  I have an admin group that only has permission to add/change/delete <strong>Invitados</strong></p>