as we configure org.ops4j.pax.web PID in http feature like
<config name="org.ops4j.pax.web">
org.osgi.service.http.port=8181
javax.servlet.context.tempdir=${karaf.data}/pax-web-jsp
org.ops4j.pax.web.config.file=${karaf.base}/etc/jetty.xml
</config>
have another org.ops4j.pax.web.cfg in etc folder is useless and it prevent to propagate properties for the ConfigAdmin service from features config tag