11197: Blank page at the checkout 'shipping' step[backport].

[nmalevanec]

Description

Blank page at the checkout 'shipping' step[backport].

Fixed Issues (if relevant)

1. Blank page at the checkout 'shipping' step #11197: Blank page at the checkout 'shipping' step

Manual testing scenarios

1. Add any product to the cart as a guest user
2. Proceed to the checkout
3. Fill address and customer data
4. Proceed to the payment step
5. Click 'Shipping' in the progress bar to return to the shipping step
6. Click next and proceed again to the payment step
7. Click 'back' button in the browser
8. Check that customer is redirected to shipping step and is able to change address data.

Contribution checklist

• Pull request has a meaningful description of its purpose
• All commits are accompanied by meaningful commit messages
• All new or changed code is covered with unit/integration tests (if applicable)
• All automated tests passed successfully (all builds on Travis CI are green)