Fix the custom properties

Hi,
When you want to associate a custom propertie label to an input of your form, only the first custom value will be fill and send to your mailjet contact properties.

This is due to an error (in think) in the cf7_to_mailjet.php file.

To get the value associate with any field of your form, you need to change code at line 276.

$data_to_mailjet = $data[$custom_label_2]

change to
$data_to_mailjet = $data[$custom_field_2]

Repeat this step until the fifth field.

With this correction, all your custom label will be filled with your wanted data