java.lang.IllegalArgumentException: Security Mapping [free access] is already registered

The error below is seen during startup. Doesn't seem to break anything so maybe should reduced to a warning.

Version

http://nexus.opendaylight.org/content/groups/staging/org/opendaylight/integration/distribution-karaf/0.2.0-Helium/distribution-karaf-0.2.0-Helium.zip

java.lang.IllegalArgumentException: Security Mapping [free access] is already registered.
at org.ops4j.pax.web.service.spi.model.ServiceModel.addSecurityConstraintMappingModel(ServiceModel.java:330)[178:org.ops4j.pax.web.pax-web-spi:3.1.0]
at org.ops4j.pax.web.service.internal.HttpServiceStarted.registerConstraintMapping(HttpServiceStarted.java:929)[179:org.ops4j.pax.web.pax-web-runtime:3.1.0]
at org.ops4j.pax.web.service.internal.HttpServiceProxy.registerConstraintMapping(HttpServiceProxy.java:356)[179:org.ops4j.pax.web.pax-web-runtime:3.1.0]
at org.ops4j.pax.web.extender.war.internal.RegisterWebAppVisitorWC.visit(RegisterWebAppVisitorWC.java:329)[185:org.ops4j.pax.web.pax-web-extender-war:3.1.0]
at org.ops4j.pax.web.extender.war.internal.model.WebApp.accept(WebApp.java:669)[185:org.ops4j.pax.web.pax-web-extender-war:3.1.0]
at org.ops4j.pax.web.extender.war.internal.WebAppPublisher$WebAppDependencyListener.register(WebAppPublisher.java:237)[185:org.ops4j.pax.web.pax-web-extender-war:3.1.0]
at org.ops4j.pax.web.extender.war.internal.WebAppPublisher$WebAppDependencyListener.addingService(WebAppPublisher.java:182)[185:org.ops4j.pax.web.pax-web-extender-war:3.1.0]