This avoids the warning "No such file or directory" if the file doesn't exist.

```
$ php artisan config:clear
unlink(/home/jellyfrog/code/librenms/bootstrap/cache/config.php): No such file or directory in /home/jellyfrog/code/librenms/vendor/laravel/framework/src/Illuminate/Filesystem/Filesystem.php on line 308

   INFO  Configuration cache cleared successfully.
```