Remove async dup codes

This reduced from

```
-rw-r--r--  1 ali  staff   826K 22 Aug 10:27 makedrive.js
-rw-r--r--  1 ali  staff   224K 22 Aug 10:27 makedrive.min.js
```

to

```
-rw-r--r--  1 ali  staff   792K 22 Aug 10:30 makedrive.js
-rw-r--r--  1 ali  staff   213K 22 Aug 10:30 makedrive.min.js
```