Docs: v2 error handling is environment independent

docs/api/index.md

@@ -193,7 +193,7 @@ app.context.db = db();
 
 ## Error Handling
 
-  By default outputs all errors to stderr unless __NODE_ENV__ is "test" or `app.silent` is `true`.
+  By default outputs all errors to stderr unless `app.silent` is `true`.
   The default error handler also won't outputs errors when `err.status` is `404` or `err.expose` is `true`.
   To perform custom error-handling logic such as centralized logging you can add an "error" event listener: