minor #899 Typo in comment, LATE_EVENT is -512 not 512 (Danez)

This PR was merged into the 1.2.x-dev branch.

Discussion
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Typo in comment, LATE_EVENT is -512 not 512

Commits
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46d20b82 Typo in comment, LATE_EVENT is -512 not 512

src/Silex/EventListener/MiddlewareListener.php

@@ -88,7 +88,7 @@ class MiddlewareListener implements EventSubscriberInterface
     public static function getSubscribedEvents()
     {
         return array(
-            // this must be executed after the late events defined with before() (and their priority is 512)
+            // this must be executed after the late events defined with before() (and their priority is -512)
             KernelEvents::REQUEST  => array('onKernelRequest', -1024),
             KernelEvents::RESPONSE => array('onKernelResponse', 128),
         );