Fix test

tests/Monolog/Handler/BufferHandlerTest.php

@@ -43,7 +43,7 @@ class BufferHandlerTest extends TestCase
         $handler = new BufferHandler($test);
         $handler->handle($this->getRecord(Logger::WARNING));
         $handler->handle($this->getRecord(Logger::DEBUG));
-        unset($handler);
+        $handler->__destruct();
         $this->assertTrue($test->hasWarningRecords());
         $this->assertTrue($test->hasDebugRecords());
     }