Fix a newline issue in "arc" workflows
Fix a newline issue in "arc" workflows

Summary:
We end up with one too few newline here in some workflows, like `arc land` with unstaged changes.

Root issue here is that `phutil_console_prompt|confirm` lead with too much whitespace but that's a harder fix.

Test Plan: Saw reasonable whitespace.

Reviewers: btrahan, chad

Reviewed By: chad

Subscribers: epriestley

Differential Revision: https://secure.phabricator.com/D11927

julkiewicz/arcanist,julkiewicz/arcanist,julkiewicz/arcanist,julkiewicz/arcanist