Console error

Browser's console error after running with `$ go run webServer.go`
```sh
Uncaught (in promise)
TypeError: WebAssembly.instantiate(): Import #0 module="env"
error: module is not an object or function
```

It works if using TinyGo's v0.6.0's wasm_exec.js instead of master
https://github.com/tinygo-org/tinygo/blob/v0.6.0/targets/wasm_exec.js
