Add null user check
Add null user check

Prevent `Trying to get property of non-object` if email doesn't exist in user table
mashy-industries/passport,laravel/passport,nueko/passport,nueko/passport,html5facil/passenger,refactory-id/passport-student,justty/passport,emiliopedrollo/passport,emiliopedrollo/passport,mashy-industries/passport,html5facil/passenger,refactory-id/passport-student,justty/passport