Cast null settings to empty array so Hash::get works as expected

[dan-steele]

Hey,

The upload blows up with an InvalidArgumentException when I have the following set in the table

$this->addBehavior('Josegonzalez/Upload.Upload', ['file']);

because $settings gets passed as null and Hash::get doesn't handle it properly. It works find when I do

$this->addBehavior('Josegonzalez/Upload.Upload', ['file' => []]);

but I think it's better to handle it here.

[josegonzalez]

How about:

$settings = $settings ?: [];

[jorisvaesen]

How about:
$settings = is_array($settings) ? $settings : [];
to prevent
['field' => true]
from passing and giving errors afterwards

[josegonzalez]

Fine by me. Can you add a test for that?

[josegonzalez]

@dan-steele bump

[jorisvaesen]

After some testing if found out this issue actually starts at initialize().
When passing in settings as ['field'], it actually becomes [0 => 'field', 'field' => null] after.
So i guess the config should be dropped before this line: https://github.com/josegonzalez/cakephp-upload/blob/master/src/Model/Behavior/UploadBehavior.php#L28

[josegonzalez]

Closed by #378