Fix keyerror when submitting a clearcase review request containing binary files changes

Review Request #6758 — Created Jan. 12, 2015 and submitted — Latest diff uploaded

Information

Review Board
release-2.0.x
17420cf...

Reviewers

Binary files has no origFile and newFile defined in their header

PS: It was originally reported by Piotr Zwara on github, I have not found any issue in reviewboard bugtracker
https://github.com/reviewboard/reviewboard/commit/2939338493658ce6424d1efc63e010e4b8290bb8#commitcomment-6777854

can upload successfully a clearcase review request containing binary file changes against reviewboard server 2.0.6 + this fix