Remove global-hook.js file from plain shell

This file was no longer used. The `container` entrypoint sets up the global hook
instead.

Author: kassens

shells/plain/global-hook.js

@@ -14,7 +14,6 @@ module.exports = {
   entry: {
     backend: './backend.js',
     container: './container.js',
-    globalHook: './global-hook.js',
   },
   output: {
     path: __dirname + '/build',