Fix buffer warning

[bastien-roucaries]

Could you apply the following patch ?

ommit 8ef945dad2a3c5223bf92f1431c6899380593c29 (HEAD -> patched)
Author: Bastien Roucariès <rouca@debian.org>
Date:   Wed Sep 1 18:51:22 2021 +0000

    Fix buffer deprecation
    
    Replace by correct API
    
    Forwarded

diff --git a/test/multi-byte.js b/test/multi-byte.js
index 7ad4d57..a753098 100644
--- a/test/multi-byte.js
+++ b/test/multi-byte.js
@@ -3,7 +3,7 @@ var unpack = require('../');
 var fs = require('fs');
 
 var src = fs.readFileSync(__dirname + '/files/utf-8.js', 'utf8');
-var buf = new Buffer(src);
+var buf = new Buffer.from(src);
 
 test('multi-byte characters', function (t) {
     t.plan(6);