Fix "none" in SVN XML summary

Summary: The `svn diff --xml --summarize` command reports a bunch of item statuses, which may include "none" if you make property changes to a directory (this is fairly rare).

Test Plan: Created property changes, saw "none" status.

Reviewers: chad, mbishopim3

Reviewed By: chad

CC: aran

Differential Revision: https://secure.phabricator.com/D4978