Removed deprecated array_get and used Arr::get() in in Setting.php

[bosunski]

Summary of Change

The use of array_get results in undefined function in Laravel 6 because of the deprecated (now removed) array_* functions in Laravel 6.

I replaced array_get with Arr::get to make this work.

[cendekia]

merge this please, my laravel nova package is dependent on this awesome package Thank you

[buibr]

You need to merge this pr is not working on 7.x