llvmbot monitor: Handle missing complete_at field

For some reason just now we were getting a successful build
without a completed time. That's fixed itself now but I might as
well add the code I wrote to handle it anyway.

Probably a glitch on Buildbot's side.

Change-Id: I049da16cf126865ce7d054eca8677da10a3377dc
1 file changed
tree: a73e164109392d407b318e6c4a0e869ce7769c04
  1. bisect/
  2. helpers/
  3. monitor/
  4. release/
  5. stress/
  6. test-suite/
  7. .gitreview
  8. README.txt