Don't return null item redirects from children view

To spot check:

1.  Create a root page (slug: "root_doc")
2.  Create a child page
3.  Move the child page
4.  (In theory, the root page has 2 docs:  one a redirect, one not)
5.  Go to "/en-US/docs/root_doc$children"
6.  The redirect should not be listed.