We already had a patch to warn users they need HTTPS when they login.
This was not working for the register form.
- Added a warning during the submit of the register form.
- Changed the check to see if `crypto.subtle` is defined or not.
- Removed the `webpack.config.js` patch, since this now is in upstream.
- Updated README.md shields and small comment regarding how to create
the patch because of changes to the submodule.