Built release app not working for me with v2.6.2, worked with v2.6.1

Hi. Sorry, this isn't going to be a very useful bug report, since I don't have a small reproducible case.

But as an FYI/heads-up, when I update electron-webpack from v2.6.1 to v2.6.2 (and make no other changes to my setup), my release app stops working. It has something to do with `react-redux`. Here are the details FWIW:

* Running on MacOS Mojave, with the latest versions of `react-redux`(v6.0.1) and latest versions of every other library.

* Dev server works fine with v2.6.2

* In the release app (created via `electron-webpack && electron-builder`), my connected components aren't updating after changes to the redux store. Or at least my top-level container isn't updating, so I don't get off my "home page" so don't know see if any of the other components would update.

TL;DR: I've poked around enough to see that react-redux's `Provider` handler that's subscribed to the redux store *is* getting called, but it doesn't in turn render the `Context` that's wrapped around the component. I haven't had the opportunity to delve even deeper to track down why.

* If, rather than importing react-redux from `node_modules` (which uses `react-redux/lib`) I instead copy `react-redux/src` into my app's source tree, then the built app works fine. So maybe there's some compatibility issue with the prebuilt files in `react-redux/lib`?

Of course this might be a react-redux issue rather than an electron-webpack issue. Or some weird problem in my own code.

But since the only change in my setup is the electron-webpack patch version I figured I'd at least start by mentioning it here, in case this description sparks a thought for somebody else. Thanks for listening! :)

Start by comparing release builds made with electron-webpack v2.6.1 and v2.6.2 using electron-builder, then inspect the difference between react-redux/lib and react-redux/src. Reproduce the case on the reported setup and verify that connected components update after Redux store changes in the built app.

Written by the indexing model from the issue text.