Stop warnings about safe typecast

Guy Paddock

27.46.2017 114516cdeb8c20f90a3c0d884effb5b145c4079b

 opendj-rest2ldap/src/main/java/org/forgerock/opendj/rest2ldap/ReadOnlyRequestHandler.java

@@ -61,6 +61,7 @@
    }

    @Override
    @SuppressWarnings("unchecked")
    public ApiDescription api(ApiProducer<ApiDescription> producer) {
        if (delegate instanceof Describable) {
            return ((Describable<ApiDescription, Request>)delegate).api(producer);