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
```
for key, value in query_map.items():
        if key.lower().startswith(OBJECT_METADATA_KEY_PREFIX):
            if headers.get(key) is None:
                headers[key] = value[0]
def fix_location_constraint(response):
    """ Make sure we return a valid non-empty LocationConstraint, as this otherwise breaks Serverless. """
    try:
        content = to_str(response.content or '') or ''
    except Exception:
        content = ''
    if 'LocationConstraint' in content:
        pattern = r'<LocationConstraint([^>]*)>\s*</LocationConstraint>'
        replace = r'<LocationConstraint\1>%s</LocationConstraint>' % aws_stack.get_region()
        response._content = re.sub(pattern, replace, content)
        remove_xml_preamble(response)
def fix_range_content_type(bucket_name, path, headers, response):
    
    if 'Range' not in headers:
        return
    s3_client = aws_stack.connect_to_service('s3')
    path = urlparse.unquote(path)
    key_name = get_key_name(path, headers)
    result = s3_client.head_object(Bucket=bucket_name, Key=key_name)
    content_type = result['ContentType']
    if response.headers.get('Content-Type') == 'text/html; charset=utf-8':
        response.headers['Content-Type'] = content_type
def fix_delete_objects_response(bucket_name, method, parsed_path, data, headers, response):