How to keep my process engine without a configuration specification

In my standalone.xml I don’t want to add any configuration for my processEngine, so I don’t have the element. But when I start my jboss, some time later I go back to see the standalone.xml and I see this:

      <configuration>
                org.camunda.bpm.container.impl.jboss.config.ManagedJtaProcessEngineConfiguration
      </configuration>

How can I stop this? I want my standalone.xml to remain without that tag!

my subsystem configuration for camunda is as follows:

<subsystem xmlns="urn:org.camunda.bpm.jboss:1.1">
    <process-engines>
        <process-engine name="default" default="true">
            <datasource>
                java:jboss/datasources/EpsilonXADS
            </datasource>
            <history-level>
                audit
            </history-level>
            <properties>
                <property name="jobExecutorAcquisitionName">
                    default
                </property>
                <property name="isAutoSchemaUpdate">
                    true
                </property>
                <property name="authorizationEnabled">
                    true
                </property>
                <property name="jobExecutorDeploymentAware">
                    true
                </property>
                <property name="executionTreePrefetchEnabled">
                    false
                </property>
                <property name="jobExecutorActivate">
                    true
                </property>
            </properties>
            <plugins>
                <plugin>
                    <class>
                        org.camunda.bpm.application.impl.event.ProcessApplicationEventListenerPlugin
                    </class>
                </plugin>
            </plugins>
        </process-engine>
    </process-engines>
    <job-executor>
        <thread-pool-name>
            job-executor-tp
        </thread-pool-name>
        <job-acquisitions>
            <job-acquisition name="default">
                <acquisition-strategy>
                    SEQUENTIAL
                </acquisition-strategy>
                <properties>
                    <property name="lockTimeInMillis">
                        300000
                    </property>
                    <property name="waitTimeInMillis">
                        8000
                    </property>
                    <property name="maxJobsPerAcquisition">
                        10
                    </property>
                </properties>
            </job-acquisition>
        </job-acquisitions>
    </job-executor>
</subsystem>

Thanks in advance.