Handle nil output when writing progress message
Created by: olafurpg
Previously, the command src lsif upload -no-progress
failed with a
nil panic when using LSIF Typed. I was tempted to refactor the code
so that output
cannot be nil but decided not to in order to keep the
diff small and focused on fixing the panic.
Test plan
Manually ran src lsif upload -no-progress
and see it not panic.