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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)

...

def execute_java_lambda(self, event, context, main_file, func_details=None):
        handler = func_details.handler
        opts = config.LAMBDA_JAVA_OPTS if config.LAMBDA_JAVA_OPTS else ''
        event_file = EVENT_FILE_PATTERN.replace('*', short_uid())
        save_file(event_file, json.dumps(json_safe(event)))
        TMP_FILES.append(event_file)
        class_name = handler.split('::')[0]
        classpath = '%s:%s:%s' % (main_file, Util.get_java_classpath(main_file), LAMBDA_EXECUTOR_JAR)
        cmd = 'java %s -cp %s %s %s %s' % (opts, classpath, LAMBDA_EXECUTOR_CLASS, class_name, event_file)
        LOG.warning(cmd)
        result = self.run_lambda_executor(cmd, func_details=func_details)
        return result
class Util:
    debug_java_port = False
    @classmethod
    def get_java_opts(cls):
        opts = config.LAMBDA_JAVA_OPTS or ''
        
        if '_debug_port_' in opts:
            if not cls.debug_java_port:
                cls.debug_java_port = get_free_tcp_port()
            opts = opts.replace('_debug_port_', ('%s' % cls.debug_java_port))
        else:
            
            m = re.match('.*address=(\\d+).*', opts)
            if m is not None:
                cls.debug_java_port = m.groups()[0]
        return opts
    @classmethod
    def get_host_path_for_path_in_docker(cls, path):