minor symfony#6670 Fix typo 'even' >> 'event' in event_listener.rst (kuusas)

This PR was submitted for the master branch but it was merged into the 2.7 branch instead (closes symfony#6670).

Discussion
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Fix typo 'even' >> 'event' in event_listener.rst

Commits
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59fc549 Fix typo 'even' >> 'event' in event_listener.rst

Author: wouterj

cookbook/event_dispatcher/event_listener.rst

@@ -65,7 +65,7 @@ The most common way to listen to an event is to register an **event listener**::
     Each event receives a slightly different type of ``$event`` object. For
     the ``kernel.exception`` event, it is :class:`Symfony\\Component\\HttpKernel\\Event\\GetResponseForExceptionEvent`.
     To see what type of object each event listener receives, see :class:`Symfony\\Component\\HttpKernel\\KernelEvents`
-    or the documentation about the specific even you're listening to.
+    or the documentation about the specific event you're listening to.
 
 Now that the class is created, you just need to register it as a service and
 notify Symfony that it is a "listener" on the ``kernel.exception`` event by