Fix a regression in landing the current branch.
Review Request #6728 — Created Jan. 2, 2015 and submitted — Latest diff uploaded
A fix I made for landing a specified branch broke landing the current branch. This broke because the new code was unconditionally placing the branch name parameter into the command arguments list, but if unspecified, it was placing None in that list, which wasn't a valid value. We now conditionally insert it.
Landed the current branch successfully.