Fuseki filter: pass on requests that are not matched.

Taken from users@ thread.

A request /dataset/name is routed first to "dataset" then "name" looked up in the services. If "name" is not found, a 404 is generated by the Fuseki dispatcher.

If, instead, the Fuseki dispatcher just leaves the request alone, the name can be provided by a plain servlet or static file in conventional request routing by the container.