[git-cl] Fix crash in "git cl upload"
[git-cl] Fix crash in "git cl upload"

This occurs when the command is run on autorollers.

Change-Id: I264b85e906617412538b333b06414479b4acc386
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/tools/depot_tools/+/1637360
Reviewed-by: Edward Lesmes <d05609f027dc667cc37492b1dc1bdea5d60fa82a@chromium.org>
Commit-Queue: Eric Boren <0e499112533c8544f0505ea0d08394fb5ad7d8fa@chromium.org>

CoherentLabs/depot_tools,CoherentLabs/depot_tools