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
```
environment['DOCKER_LAMBDA_USE_STDIN'] = '1'
        return event_body.encode()
    def prepare_execution(self, func_arn, env_vars, runtime, command, handler, lambda_cwd):
        entrypoint = ''
        if command:
            entrypoint = ' --entrypoint ""'
        else:
            command = '"%s"' % handler
        
        network = config.LAMBDA_DOCKER_NETWORK
        network_str = '--network="%s"' % network if network else ''
        if network == 'host':
            port = str(self.next_port + self.port_offset)
            env_vars['DOCKER_LAMBDA_API_PORT'] = port
            env_vars['DOCKER_LAMBDA_RUNTIME_PORT'] = port
            self.next_port = (self.next_port + 1) % self.max_port
        env_vars_string = ' '.join(['-e {}="${}"'.format(k, k) for (k, v) in env_vars.items()])
        debug_docker_java_port = '-p {p}:{p}'.format(p=Util.debug_java_port) if Util.debug_java_port else ''
        docker_cmd = self._docker_cmd()
        docker_image = Util.docker_image_for_runtime(runtime)
        rm_flag = Util.get_docker_remove_flag()
        if config.LAMBDA_REMOTE_DOCKER:
            cmd = (
                'CONTAINER_ID="$(%s create -i'
                ' %s'  
                ' %s'  
                ' %s'