Continue processing url after sending to amqp (fetch, etc). Solves 2 problems, 1) crawl finishing after sending off umbra seeds and before umbra has a chance to send anything back, and 2) seeds sent to umbra not being fetched because they were already seen. We may want to change this in the future as umbra gets fancier, e.g. sending back html from DOM, but for now it should work.