grpc-js: hang when no server available on Windows

### Problem description
Attempting to connect to an unavailable server on Windows the grpc-js library will hang forever instead of returning `UNAVAILABLE` as is done on other platforms (specifically tested with OSX).

I have modified the node example from the grpc repo to use `@gprc/grpc-js` and output errors to the console to minimally show this happening.

### Reproduction steps
1. Clone https://github.com/mpminardi/grpc/tree/windows-hang-example
2. `cd` into `examples/node` and run `npm install`
3. Run `node ./static_codegen/greeter_client.js` from within that directory
4. Observe that the process does not exit on Windows (similar to below output)

#### Windows output

#### Mac Output

### Environment
- OS: Windows 10 Version 1809 (OS Build 17763.914)
- Node version: 12.4
- Package name and version: grpc-js 0.6.15