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
```
---
        operationId: 'invokeFunction'
        parameters:
            - name: 'request'
              in: body
    """
    
    arn = func_arn(function)
    
    m = re.match('(arn:aws:lambda:.*:.*:function:[a-zA-Z0-9-_]+)(:.*)?', arn)
    if m and m.group(2):
        qualifier = m.group(2)[1:]
        arn = m.group(1)
    else:
        qualifier = request.args.get('Qualifier')
    data = request.get_data()
    if data:
        data = to_str(data)
        try:
            data = json.loads(data)
        except Exception:
            try:
                
                data = json.loads(parse_chunked_data(data))
            except Exception:
                return error_response('The payload is not JSON: %s' % data, 415,
                                      error_type='UnsupportedMediaTypeException')
    
    invocation_type = request.environ.get('HTTP_X_AMZ_INVOCATION_TYPE', 'RequestResponse')
    def _create_response(result, status_code=200):