[ERROR] Failed to execute goal org.wildfly.plugins:wildfly-maven-plugin:1.1.0.Alpha11:undeploy-artifact (undeploy-app-gui) on project app-gui: Failed to undeploy app-gui.war. Reason: No server groups were defined for the deployment operation. Deployment: UndeployDescription(name=app-gui.war, failOnMissing=false, removeContent=true) -> [Help 1]

<plugin>
    <groupId>org.wildfly.plugins</groupId>
    <artifactId>wildfly-maven-plugin</artifactId>
    <version>1.1.0.Alpha11</version>
    <configuration>
        <hostname>${deployment.hostname}</hostname>
        <port>${deployment.port}</port>
        <username>${deployment.username}</username>
        <password>${deployment.password}</password>
    </configuration>
</plugin>

<execution>
    <id>undeploy-app-gui</id>
    <phase>validate</phase>
    <goals>
        <goal>undeploy-artifact</goal>
    </goals>
    <configuration>
        <ignoreMissingDeployment>true</ignoreMissingDeployment>
        <groupId>com.example.app</groupId>
        <artifactId>app-gui-deployable</artifactId>
        <name>app-gui.war</name>
        <domain>
            <server-groups>
                <server-group>app-www</server-group>
            </server-groups>
        </domain>
    </configuration>
</execution>