Wrong schema may be returned from LSResourceResolver.resolveResource() with null system ID

This is related to CXF-2609's fix for EndpointReferenceUtils:

if (ent.getKey().endsWith(namespaceURI)) {

I believe this should be:

if (ent.getKey().endsWith(":" + namespaceURI)) {

Otherwise this can return the wrong schema entry in the case of 2 schema where one's namespace is a prefix + the other namespace.