Can't have command-line argument "--module" in Node 12

Some of my Grunt tasks take a "--module=..." argument. Under Node 8.15.0, things work fine:

```
$ grunt --hello=asdf
Warning: Task "default" not found. Use --force to continue.

Aborted due to warnings.
$ grunt --module=asdf
Warning: Task "default" not found. Use --force to continue.
```

Under Node 10 and above, something goes wrong when I use "--module=...".

```
$ grunt --hello=asdf
Warning: Task "default" not found. Use --force to continue.

Aborted due to warnings.
$ grunt --module=asdf
/Users/kannan/.nodenv/versions/10.17.0/bin/node: bad option: --module=asdf
```