`GTMSessionUploadFetcher` endlessly sends empty chunks when `uploadFileURL` points to an empty or non-existing file

[maksymmalyhin]

Issues like this is an implication of this issue.

[thomasvl]

What is #2350? This project doesn't have an issue with that number.

[maksymmalyhin]

@thomasvl Ah, sorry, I need to add a global link, since it is an issue from another project: firebase/firebase-ios-sdk#2350

[maksymmalyhin]

@thomasvl I think, I can provide a fix for the issue. Would you mind me doing that?
cc @ryanwilson

[thomasvl]

@thomasvl I think, I can provide a fix for the issue. Would you mind me doing that?

Nope, go for it!

[thomasvl]

I believe that PR fixed this.