Webpack DLLs Validation Bug

[arfianadam]

In local development, our configuration of webpack will try to use DLLs. First it will try to check whether the dlls exists or not, and try to validate it by matching the hash. However there is a bug in the function where it does its checking.

https://github.com/bertho-zero/react-redux-universal-hot-example/blob/master/webpack/helpers.js#L61

path.join(assetsPath, `dlls/dll__${dllName}.js`, 'utf8') will always return false as it will try to find dlls/dll_vendor.js/utf8 which is nonsense. The intention of this line is to read the file with utf8 encoding. So there's the bug.

I'm pushing something to fix this. Just a small fix.