Update Behaviors.rst (french)

Add use "Cake\ORM\Query to "Définir des Event Listeners" example code
Update Behaviors.rst 

Add "use Cake\ORM\Query" to "Defining Event Listeners" example code
Merge pull request #1845 from bouksou/patch-2

Update Behaviors.rst
Merge pull request #1843 from bouksou/patch-1

Update Behaviors.rst (french)