bytesize instead of length

package.json

@@ -1,6 +1,6 @@
 {
   "name": "flummpress",
-  "version": "2.0.6",
+  "version": "2.0.7",
   "description": "Express für arme",
   "main": "src/index.mjs",
   "repository": {

src/index.mjs

@@ -1,5 +1,6 @@
 import http from "http";
 import { URL } from "url";
+import { Buffer } from "buffer";
 import querystring from "querystring";
 
 import Router from "./router.mjs";
@@ -110,7 +111,7 @@ export default class flummpress {
     }) => {
       res.writeHead(code, {
         "content-type": `${type}; charset=UTF-8`,
-        "content-length": body.length
+        "content-length": Buffer.byteLength(body, 'utf-8')
       });
       if(res.method === 'HEAD')
         body = null;