Upgrade Protobuf.js 6 code to work with 6.8

src/protobuf_js_6_common.js

@@ -64,7 +64,7 @@ exports.deserializeCls = function deserializeCls(cls, options) {
    * @return {cls} The resulting object
    */
   return function deserialize(arg_buf) {
-    return cls.decode(arg_buf).toObject(conversion_options);
+    return cls.toObject(cls.decode(arg_buf), conversion_options);
   };
 };