You cron log reports this message :
No lang selected, nothing to do ...
You configured the cron job to execute this command line :
wget -qO- http://votredomaine.com/prestashop/modules/amazonv4/functions/products.php?cron=1
You should add double quotes to protect your URL, as this :
wget -qO- “http://votredomaine.com/prestashop/modules/amazonv4/functions/products.php?cron=1”
We just added double quotes to the URL.