mjs files get imported as static files

Created by: jgoux

Hello,

Here is a repro :

import graphql, { parse, buildASTSchema, buildClientSchema } from 'graphql'
console.log(graphql, parse, buildASTSchema, buildClientSchema)
// ouput : /static/media/index.497f5ee2.mjs undefined undefined undefined

Excluding the .mjs extension from the file-loader fix the issue.