It seems to be fixed in current version of maven-war-plugin, so just specifying:

<plugin>
        <artifactId>maven-war-plugin</artifactId>
        <version>2.3</version>
    </plugin>

fixed it for me. (See the last answer (20/Sep/12 4:37 AM) from Anders Hammar on https://issues.apache.org/jira/browse/MWAR-248.)