v4 does not use updated non-React modules

### Description

If a React module depends on a module that is not a React component and the non-React module is updated, the code is hot reloaded but the React module does not use the updated non-React module. This was working in v3 and seems like it should work automatically when using ES2015 modules.

### Expected behavior

The React module should use the updated non-React module.
This was working as expected with `react-hot-loader@3.1.3`.

### Actual behavior

The React module continues to use the old non-React module.

### Environment

React Hot Loader version: `4.1.2`, `4.3.0+`

Irrelevant version info
1. `node -v`: 10.15.1
2. `npm -v`: 6.4.1

And

1. Operating system: Windows 10
2. Browser and version: Chrome 72

### Reproducible Demo

https://github.com/nwoltman/rhl-bug-repro

Follow the instructions in the README. When you modify the `sanitizeEmail` function, the console shows that HMR worked, but when you type in the text input on the page, it seems to still be using the old `sanitizeEmail` function.

If you change the `react-hot-loader` version in `package.json` to ~~`3.1.3` (and uncomment `'react-hot-loader/patch'` in `webpack.config.js`)~~ `4.2.0` (this bug was temporarily patched in that version), it works as expected.