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
```
Exception,
            apig.get_authorizer,
            self.TEST_API_GATEWAY_ID,
            authorizer_id)
    def _test_api_gateway_lambda_proxy_integration_any_method(self, fn_name, path):
        self.create_lambda_function(fn_name)
        
        lambda_uri = aws_stack.lambda_function_arn(fn_name)
        target_uri = aws_stack.apigateway_invocations_arn(lambda_uri)
        result = self.connect_api_gateway_to_http_with_lambda_proxy(
            'test_gateway3', target_uri, methods=['ANY'], path=path)
        
        path = path.replace('{test_param1}', 'foo1')
        url = self.gateway_request_url(
            api_id=result['id'], stage_name=self.TEST_STAGE_NAME, path=path)
        data = {}
        for method in ('GET', 'POST', 'PUT', 'PATCH', 'DELETE', 'OPTIONS'):
            body = json.dumps(data) if method in ('POST', 'PUT', 'PATCH') else None
            result = getattr(requests, method.lower())(url, data=body)
            self.assertEqual(result.status_code, 200)
            parsed_body = json.loads(to_str(result.content))
            self.assertEqual(parsed_body.get('httpMethod'), method)
    # =====================================================================
    # Helper methods
    # =====================================================================
    def gateway_request_url(self, api_id, stage_name, path):
        """ Return URL for inbound API gateway for given API ID, stage name, and path """
        pattern = '%s/restapis/{api_id}/{stage_name}/%s{path}' % (config.TEST_APIGATEWAY_URL, PATH_USER_REQUEST)
        return pattern.format(api_id=api_id, stage_name=stage_name, path=path)
    def connect_api_gateway_to_kinesis(self, gateway_name, kinesis_stream):