when I try to upload a large file, localstack basically freezes (and eventually times out).  
But if the file is all `1` bytes it succeeds.

succeeds:
```bash
aws s3 --endpoint-url=http://localhost:4572 mb s3://testbucket
python -c "print '\x01'*10000000" > testfile
echo $(ls -ahl | grep testfile)
aws s3 --endpoint-url=http://localhost:4572 cp testfile s3://testbucket/testfile
```

fails:
```bash
aws s3 --endpoint-url=http://localhost:4572 mb s3://testbucket
python -c "print 'a'*10000000" > testfile
echo $(ls -ahl | grep testfile)
aws s3 --endpoint-url=http://localhost:4572 cp testfile s3://testbucket/testfile
```
so, for me, both the file content and its size determine if this triggers or not. 
I'm using the latest version `0.9.5`
bucket_name = 'test-bucket-%s' % short_uid()
        key = 'test.file'
        hostname_before = config.HOSTNAME_EXTERNAL
        config.HOSTNAME_EXTERNAL = 'foobar'
        try:
            content = 'test content 123'
            acl = 'public-read'
            self.s3_client.create_bucket(Bucket=bucket_name)
            
            response = self._perform_multipart_upload(bucket=bucket_name, key=key, data=content, acl=acl)
            expected_url = '%s://%s:%s/%s/%s' % (get_service_protocol(), config.HOSTNAME_EXTERNAL,
                config.PORT_S3, bucket_name, key)
            self.assertEqual(expected_url, response['Location'])
            
            self.s3_client.put_object_acl(Bucket=bucket_name, Key=key, ACL=acl)
            
            downloaded_object = self.s3_client.get_object(Bucket=bucket_name, Key=key)
            self.assertEqual(to_str(downloaded_object['Body'].read()), content)
            
            download_url = response['Location'].replace('%s:' % config.HOSTNAME_EXTERNAL, 'localhost:')
            response = safe_requests.get(download_url)
            self.assertEqual(response.status_code, 200)
            self.assertEqual(to_str(response.content), content)
        finally:
            config.HOSTNAME_EXTERNAL = hostname_before
    def test_s3_website_errordocument(self):