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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)

...

import psutil
        if getattr(self, 'stopped', False):
            return
        if not self.process:
            LOG.warning("No process found for command '%s'" % self.cmd)
            return
        parent_pid = self.process.pid
        try:
            parent = psutil.Process(parent_pid)
            for child in parent.children(recursive=True):
                child.kill()
            parent.kill()
            self.process = None
        except Exception:
            if not quiet:
                LOG.warning('Unable to kill process with pid %s' % parent_pid)
        self.stopped = True
class JsonObject(object):
    """ Generic JSON serializable object for simplified subclassing """
    def to_json(self, indent=None):
        return json.dumps(self,
            default=lambda o: ((float(o) if o % 1 > 0 else int(o))
                if isinstance(o, decimal.Decimal) else o.__dict__),
            sort_keys=True, indent=indent)
    def apply_json(self, j):