Register and sign in buttons in checkout are stuck in loading state

[jamesporl]

Issue Description

Register and sign in buttons in checkout are stuck in loading state when email address and password are empty.

Steps to Reproduce

1. As an anonymous consumer, add a product to your cart.
2. Checkout.
3. Leaving email and password fields empty, click Register.
4. Observe that the button gets stuck at showing the spinner and the browser console displays:

Uncaught TypeError: Cannot read property 'trim' of null
    at Object.email (account-validation.js:50)
    at AuthContainer.handleFormSubmit (auth.js:24)
    at SignUp.handleSubmit.event (signUp.js:18)
    at HTMLUnknownElement.callCallback (modules.js?hash=69f0a557d2146cce696d30ed0217c3fe2615ba47:195880)
    at Object.invokeGuardedCallbackDev (modules.js?hash=69f0a557d2146cce696d30ed0217c3fe2615ba47:195918)
    at Object.invokeGuardedCallback (modules.js?hash=69f0a557d2146cce696d30ed0217c3fe2615ba47:195967)
    at Object.invokeGuardedCallbackAndCatchFirstError (modules.js?hash=69f0a557d2146cce696d30ed0217c3fe2615ba47:195981)
    at executeDispatch (modules.js?hash=69f0a557d2146cce696d30ed0217c3fe2615ba47:196241)
    at executeDispatchesInOrder (modules.js?hash=69f0a557d2146cce696d30ed0217c3fe2615ba47:196263)
    at executeDispatchesAndRelease (modules.js?hash=69f0a557d2146cce696d30ed0217c3fe2615ba47:196361)

5. Do the same steps for sign in.

Possible Solution

None

Versions

Node: 8.11.2
NPM: 5.6.0
Meteor Node: 8.11.3
Meteor NPM: 5.10.0
Reaction CLI: 0.29.0
Reaction: 1.14.0
Reaction branch: release-1.14.0
Docker: 18.03.1-ce

[pardyot]

Hey folks,
I've found this interesting project would love to contribute to it. I'm working on a PR for this issue. I've already gone through the contributing guidelines. Will try to create a PR soon.

Cheers!