[Security] fixed English grammar in exception message

src/Symfony/Component/Security/Core/Exception/SessionUnavailableException.php

@@ -16,7 +16,7 @@ namespace Symfony\Component\Security\Core\Exception;
  *
  * Possible reasons for this are:
  *
- *     a) The session timed-out because the user waited too long.
+ *     a) The session timed out because the user waited too long.
  *     b) The user has disabled cookies, and a new session is started on each
  *        request.
  *

src/Symfony/Component/Security/Http/Firewall/AbstractAuthenticationListener.php

@@ -133,7 +133,7 @@ abstract class AbstractAuthenticationListener implements ListenerInterface
 
         try {
             if (!$request->hasPreviousSession()) {
-                throw new SessionUnavailableException('Your session has timed-out, or you have disabled cookies.');
+                throw new SessionUnavailableException('Your session has timed out, or you have disabled cookies.');
             }
 
             if (null === $returnValue = $this->attemptAuthentication($request)) {