When PUTting an S3 object to Localstack with attached Metadata, if a key contains an underscore it is replaced with a dash.

However, when the same request is performed against the real S3, the key is not modified.

Example Input:
key_with_underscores => test

Localstack Result:
key-with-underscores => test

S3 Result:
key_with_underscores => test

Localstack Version: 0.10.5

Tested using AWS v2 S3 client
path = to_str(path)
        method = to_str(method)
        bucket_name = get_bucket_name(path, headers)
        
        hostname_parts = headers['host'].split('.')
        if (not bucket_name or len(bucket_name) == 0) and len(hostname_parts) > 1:
            bucket_name = hostname_parts[0]
        
        
        
        key = None
        if method == 'POST':
            key, redirect_url = multipart_content.find_multipart_key_value(data, headers)
            if key and redirect_url:
                response.status_code = 303
                response.headers['Location'] = expand_redirect_url(redirect_url, key, bucket_name)
                LOGGER.debug('S3 POST {} to {}'.format(response.status_code, response.headers['Location']))
            key, status_code = multipart_content.find_multipart_key_value(
                data, headers, 'success_action_status')
            if response.status_code == 200 and status_code == '201' and key:
                response.status_code = 201
                response._content = self.get_201_reponse(key, bucket_name)
                response.headers['Content-Length'] = str(len(response._content))
                response.headers['Content-Type'] = 'application/xml; charset=utf-8'
                return response
        parsed = urlparse.urlparse(path)
        bucket_name_in_host = headers['host'].startswith(bucket_name)
        should_send_notifications = all([