git push with https opens credential dialog with misleading labels

[ungb]

repro:

1. Checkout repo with https: git clone https://github.com/ungb/public-repo.git
2. open on atom atom public-repo
3. Open a file, and on the bottom right, click on the up and down arrow and try to push.

Expected:
Credential Dialog ask for Username and then PW

Actual:
The Username credential dialog ask for username but labels the field as password which is confusing.

Versions

Atom Version (atom --version):
Atom : 1.16.0
Electron: 1.3.13
Chrome : 52.0.2743.82
Node : 6.5.0

GitHub Package Version (git --git-dir ~/.atom/packages/github/.git rev-parse head):
09961fe

[smashwilson]

I suspect this is related to #652; git falls back to SSH_ASKPASS if the credential handler isn't configured correctly.