Fixed 'Array to string conversion' error

Fixed 'Array to string conversion' error when Cron job arguments are in a multidimensional array with clear indication of the fact that the arguments are in a multidimensional array.

The issue addressed is the same as pull request #14. I had already fixed this myself before I found this repo.

The difference between pull request #14 and this fix is, that the changes in #14 will flatted the nested array and show all (grand-)children as equal, while with the fix included in this pull request, you will get an indication that the argument is an array including indenting based on array-depth.

Hope this helps & keep up the good work!