Moving javascript driver back to platform (#3613)

webapp/utils/post_utils.jsx

@@ -1,7 +1,7 @@
 // Copyright (c) 2016 Mattermost, Inc. All Rights Reserved.
 // See License.txt for license information.
 
-import Client from 'utils/web_client.jsx';
+import Client from 'client/web_client.jsx';
 import Constants from 'utils/constants.jsx';
 
 export function isSystemMessage(post) {