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# Type of request: This is a ...

[x] bug report
[ ] feature request

# Detailed description

In the `ReceiveMessageResult` of the SQS service, I saw this XML from localstack:

```
...
<MessageAttribute>
     <Name>encoding</Name>
    <Value>
        <DataType>String</DataType>
        <StringValue><![CDATA[gzip]]></StringValue>
    </Value>
</MessageAttribute>
...
```

The `<![CDATA[gzip]]>` is slightly different from AWS, which doesn't wrap the value in a `<!CDATA[[]]>` section. This shouldn't be a problem for XML parsers that accept both plain characters and CDATA sections for this element, but the XML parser I was using did not, which causes an error when running the code against localstack but not when running the code against AWS. There is obviously a bug in the XML parser as well, but I thought that I should at least post this here since it is different than what AWS SQS does.

## Expected behavior

MessageAttribute::Value elements should not be wrapped in `CDATA` sections.

## Actual behavior

MessageAttribute::Value elements all seem to be wrapped in `CDATA` sections.

# Steps to reproduce

Send a message to the SQS service which contains some custom message attributes, then make a ReceiveMessageRequest.

## Command used to start LocalStack

`docker run --env "SERVICES=sqs" localstack/localstack`

## Client code (AWS SDK code snippet, or sequence of "awslocal" commands)

...

response.status_code = 500
                return response
            if result is not None:
                is_chunked = uses_chunked_encoding(result)
                result_content = result.content or ''
                response = await make_response(result_content)
                response.status_code = result.status_code
                if is_chunked:
                    response.headers.pop('Content-Length', None)
                result.headers.pop('Server', None)
                result.headers.pop('Date', None)
                response.headers.update(dict(result.headers))
                
                multi_value_headers = getattr(result, 'multi_value_headers', {})
                for key, values in multi_value_headers.items():
                    for value in values:
                        response.headers.add_header(key, value)
                
                if 'Content-Length' not in response.headers and not is_chunked:
                    response.headers['Content-Length'] = str(len(result_content) if result_content else 0)
                if 'Connection' not in response.headers:
                    response.headers['Connection'] = 'close'
        return response
    def run_app_sync(*args, loop=None, shutdown_event=None):
        kwargs = {}
        config = Config()
        cert_file_name, key_file_name = ssl_creds or (None, None)
        if cert_file_name:
            kwargs['certfile'] = cert_file_name
            config.certfile = cert_file_name