Update the removal version in the deprecation message

Author: stof

DependencyInjection/Compiler/DebugHandlerPass.php

@@ -24,17 +24,17 @@
  * @author Christophe Coevoet <stof@notk.org>
  * @author Jordi Boggiano <j.boggiano@seld.be>
  *
- * @deprecated since version 2.12, to be removed in 3.0. Use AddDebugLogProcessorPass in FrameworkBundle instead.
+ * @deprecated since version 2.12, to be removed in 4.0. Use AddDebugLogProcessorPass in FrameworkBundle instead.
  */
 class DebugHandlerPass implements CompilerPassInterface
 {
     private $channelPass;
 
     public function __construct(LoggerChannelPass $channelPass)
     {
-        // Trigger the deprecation only when using a Symfony version supporting the new feature
+        // Trigger the deprecation only when using a Symfony version supporting the new feature (i.e. 3.2+)
         if (class_exists('Symfony\Bridge\Monolog\Processor\DebugProcessor') && class_exists('Symfony\Bundle\FrameworkBundle\DependencyInjection\Compiler\AddDebugLogProcessorPass')) {
-            @trigger_error('The '.__CLASS__.' class is deprecated since version 2.12 and will be removed in 3.0. Use AddDebugLogProcessorPass in FrameworkBundle instead.', E_USER_DEPRECATED);
+            @trigger_error('The '.__CLASS__.' class is deprecated since version 2.12 and will be removed in 4.0. Use AddDebugLogProcessorPass in FrameworkBundle instead.', E_USER_DEPRECATED);
         }
 
         $this->channelPass = $channelPass;