Fix two issues with Phriction "recent updates" list

Summary:
First, I broke the addIcon() call recently with bad greps.

Second, a user is reporting an issue on GitHub (https://github.com/facebook/phabricator/issues/346) which I can't reproduce but which could reasonably occur for various reasons. Don't depend on being able to find the source/target of a move.

Test Plan: Looked at recent updates in Phriction.

Reviewers: btrahan

Reviewed By: btrahan

CC: aran, seungrye

Differential Revision: https://secure.phabricator.com/D6389