Fix filter by term for publications.

#5373 

After this addition links seem to work ok on the "filter by term" for publications:
![selection_003](https://f.cloud.github.com/assets/4497748/2330966/d8fa82b2-a440-11e3-89a0-6efc8825b683.png)

Before this change the URL was ``john/publications/taxonomy/science/air`` so we got a 404.