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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)

...

if isinstance(j, str):
            j = json.loads(j)
        self.__dict__.update(j)
    def to_dict(self):
        return json.loads(self.to_json())
    @classmethod
    def from_json(cls, j):
        j = JsonObject.as_dict(j)
        result = cls()
        result.apply_json(j)
        return result
    @classmethod
    def from_json_list(cls, json_list):
        return [cls.from_json(j) for j in json_list]
    @classmethod
    def as_dict(cls, obj):
        if isinstance(obj, dict):
            return obj
        return obj.to_dict()
    def __str__(self):
        return self.to_json()
    def __repr__(self):
        return self.__str__()
class CaptureOutput(object):