sqs.changeMessageVisibility according to [this](https://docs.aws.amazon.com/AWSSimpleQueueService/latest/APIReference/API_ChangeMessageVisibility.html#API_ChangeMessageVisibility_Examples) makes a request directly to the Queue's URL rather than via the SQS Endpoint. (I'm already setting SQS endpoint to LOCALSTACK_HOSTNAME - makes no difference for this call)..

In localstack the queue URL host returned is by default set to the value of HOSTNAME_EXTERNAL, which I'm setting to localstack, but calling this method within a lambda, does not work and I get the error:

```
UnknownEndpoint: Inaccessible host: `localstack'. This service may not be available in the `us-east-1' region. 
```

So, how can I make the queue URL accessible from within a lambda using localstack? Effectively I need to make **http://localstack** accessible from within lambda.

I'm using the following cmd to start localstack:

```
LAMBDA_EXECUTOR=docker-reuse DEBUG=1 LAMBDA_REMOTE_DOCKER=0 DATA_DIR=/tmp/localstack/data HOSTNAME_EXTERNAL=localstack localstack start
```
queue_name = 'queue-%s' % short_uid()
        dlq_name = 'queue-%s' % short_uid()
        dlq_info = self.client.create_queue(QueueName=dlq_name)
        dlq_arn = aws_stack.sqs_queue_arn(dlq_name)
        attributes = {'RedrivePolicy': json.dumps({'deadLetterTargetArn': dlq_arn, 'maxReceiveCount': 100})}
        queue_url = self.client.create_queue(QueueName=queue_name, Attributes=attributes)['QueueUrl']
        
        self.client.delete_queue(QueueUrl=queue_url)
        self.client.delete_queue(QueueUrl=dlq_info['QueueUrl'])
    def test_dead_letter_queue_execution(self):
        lambda_client = aws_stack.connect_to_service('lambda')
        
        queue_name1 = 'test-%s' % short_uid()
        queue_name2 = 'test-%s' % short_uid()
        queue_url1 = self.client.create_queue(QueueName=queue_name1)['QueueUrl']
        queue_arn1 = aws_stack.sqs_queue_arn(queue_name1)
        policy = {'deadLetterTargetArn': queue_arn1, 'maxReceiveCount': 1}
        queue_url2 = self.client.create_queue(QueueName=queue_name2,
                                              Attributes={'RedrivePolicy': json.dumps(policy)})['QueueUrl']
        queue_arn2 = aws_stack.sqs_queue_arn(queue_name2)
        
        lambda_name = 'test-%s' % short_uid()
        zip_file = testutil.create_lambda_archive(load_file(TEST_LAMBDA_PYTHON),
                                                  get_content=True, libs=TEST_LAMBDA_LIBS,
                                                  runtime=LAMBDA_RUNTIME_PYTHON36)
        testutil.create_lambda_function(func_name=lambda_name, zip_file=zip_file,
                                        runtime=LAMBDA_RUNTIME_PYTHON36)