Remove webpack public path variable from index files.

dev_mode/index.js

@@ -6,10 +6,7 @@
 require('es6-promise/auto');  // polyfill Promise on IE
 
 var PageConfig = require('@jupyterlab/coreutils').PageConfig;
-// eslint-disable-next-line no-undef
-__webpack_public_path__ = PageConfig.getOption('publicUrl');
 
-// This needs to come after __webpack_public_path__ is set.
 require('font-awesome/css/font-awesome.min.css');
 
 /**

jupyterlab/staging/index.js

@@ -6,10 +6,7 @@
 require('es6-promise/auto');  // polyfill Promise on IE
 
 var PageConfig = require('@jupyterlab/coreutils').PageConfig;
-// eslint-disable-next-line no-undef
-__webpack_public_path__ = PageConfig.getOption('publicUrl');
 
-// This needs to come after __webpack_public_path__ is set.
 require('font-awesome/css/font-awesome.min.css');
 
 /**