Amended commit message does not disappear when using backspace

[kuychaco]

Repro steps:

1. Click the amend check box
2. Hit backspace until entire message is deleted

Expected: commit message box is empty
Actual: amended message comes back

Note: Highlighting entire amended commit message and deleting results in an empty commit message box. Highlighting message that is NOT the amended commit message and deleting results momentarily results in an empty message box, but then the amended commit message comes back.

Versions

Atom Version (atom --version):

GitHub Package Version (git --git-dir ~/.atom/packages/github/.git rev-parse head): 65a2403