laravel 5内置脚手架试图使用用户名而不是电子邮件错误

I already created a column username and fill it in the users table that was used with the laravel 5 built in login scaffolding and what I'm trying to do is to use username instead of the default email so I tweak the code that I found in laravel\vendor\compiled.php with the following (refer below)I already created a column username and fill it