default to null

config/database.php

@@ -117,7 +117,7 @@ return [
 
         'default' => [
             'host'     => env('REDIS_HOST', 'localhost'),
-            'password' => env('REDIS_PASSWORD', ''),
+            'password' => env('REDIS_PASSWORD', null),
             'port'     => env('REDIS_PORT', 6379),
             'database' => 0,
         ],