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
```
""" Create the final response for the given invocation result """
        if isinstance(result, Response):
            return result
        details = {
            'StatusCode': status_code,
            'Payload': result,
            'Headers': {}
        }
        if isinstance(result, dict):
            for key in ('StatusCode', 'Payload', 'FunctionError'):
                if result.get(key):
                    details[key] = result[key]
        
        was_json = False
        payload = details['Payload']
        if payload and isinstance(payload, POSSIBLE_JSON_TYPES) and payload[0] in JSON_START_CHARS:
            try:
                details['Payload'] = json.loads(details['Payload'])
                was_json = True
            except Exception:
                pass
        
        if details.get('FunctionError'):
            details['Headers']['X-Amz-Function-Error'] = str(details['FunctionError'])
        
        response_obj = details['Payload']
        if was_json or isinstance(response_obj, JSON_START_TYPES):