chore: use res instead of this.res (#1271)

mingmingwon · dead-horse · commit bc81ca941429 · 2018-11-05T17:15:58.000+08:00
diff --git a/lib/context.js b/lib/context.js
@@ -154,7 +154,7 @@ const proto = module.exports = {
     const msg = err.expose ? err.message : code;
     this.status = err.status;
     this.length = Buffer.byteLength(msg);
-    this.res.end(msg);
+    res.end(msg);
   },
 
   get cookies() {
