Update log level to use Monolog\Level::Debug (#135)

Author: wansxlysys

config/autoload/logger.php

@@ -19,7 +19,7 @@
             'class' => StreamHandler::class,
             'constructor' => [
                 'stream' => BASE_PATH . '/runtime/logs/hyperf.log',
-                'level' => Logger::DEBUG,
+                'level' => Monolog\Level::Debug,
             ],
         ],
         'formatter' => [