title: Geodjango distance query not retrieving correct results
body: <p>I am trying to retrieve some posts depending on their proximity geographically.<br>
  As you can see in the code I am using GeoDjango and the code is executed within a view.<br> 
  The issue is that the distance filter seems to be completely disregarded.</p>
  
  <p>When I check the distances on the queryset I get the expected distances (1m and 18km) but the 18km post should not have been retrieved.</p>
  
  <pre><code>def get(self, request, format=None):
      latlon=request.query_params
      pnt = GEOSGeometry('SRID=28992;POINT(%s %s)'%(latlon['lat'],latlon['lon']))
      posts = Post.objects.filter(point__distance_lte=(pnt, D(km=1)))
      serialized = PostSerializer(posts, many=True)
      for post in posts:
          distance = pnt.distance(post.point)
          print("Km distance:",distance * 100)
      return JsonResponse(serialized.data, safe=False)
  </code></pre>
  
  <p>Result:</p>
  
  <pre><code>Km distance: 0.00015231546206626192
  Km distance: 18.317378752081577
  [18/Jul/2017 13:24:35] "GET /api/posts/?lon=5.8372264&amp;lat=51.8125626 HTTP/1.1" 200 144
  </code></pre>