Fixed incorrect config import/dependancy on DeleteJob

[alexgarrettsmith]

Issue when ->delete()ing on models.

A quick side note, it might be nicer to use

$this->app = $app;
$this->config = $app->config;

for dependancy injection. If you agree, I can add this to the PR.

[alexbowers]

Need this merged. This fixes the issue.

[julianrichen]

Merging this would really be nice :)