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
```
apig = aws_stack.connect_to_service('apigateway')
        authorizer = apig.create_authorizer(
            restApiId=self.TEST_API_GATEWAY_ID,
            **self.TEST_API_GATEWAY_AUTHORIZER)
        authorizer_id = authorizer.get('id')
        create_result = apig.get_authorizer(
            restApiId=self.TEST_API_GATEWAY_ID,
            authorizerId=authorizer_id)
        # ignor
        del create_result['ResponseMetadata']
        create_expected = clone(self.TEST_API_GATEWAY_AUTHORIZER)
        create_expected['id'] = authorizer_id
        self.assertDictEqual(create_expected, create_result)
        apig.update_authorizer(
            restApiId=self.TEST_API_GATEWAY_ID,
            authorizerId=authorizer_id,
            patchOperations=self.TEST_API_GATEWAY_AUTHORIZER_OPS)
        update_result = apig.get_authorizer(
            restApiId=self.TEST_API_GATEWAY_ID,
            authorizerId=authorizer_id)
        # ignor
        del update_result['ResponseMetadata']
        update_expected = apply_patch(create_expected, self.TEST_API_GATEWAY_AUTHORIZER_OPS)
        self.assertDictEqual(update_expected, update_result)
        apig.delete_authorizer(
            restApiId=self.TEST_API_GATEWAY_ID,
            authorizerId=authorizer_id)
        self.assertRaises(