Fix small bug when loading package config files

I think there is a small bug um mako cascading path when loading config files in a package.

The generated paths are:

-> app/config/packages/foobar/config_file.php
-> app/foobar/config/config_file.php

So looks like the function is generating the right path to load config in app/config but is generating wrong path to default package tree.
Merge pull request #97 from aldoanizio/patch-2

Fix small bug when loading package config files