Fix helloworld example docker command

[kohashi]

@stanley-cheung 's update is really great!
#852

But the example Docker command didn't have port mapping, therefore it's not work in my environment (and probably anyone else's).

[linux-foundation-easycla]

The committers are authorized under a signed CLA.

• ✅ kohashi85 (0cdecb8)

[stanley-cheung]

I distinctly remember that running with --network=host on my linux machine gives a warning that those -p parameters will be ignored. And running with just --network=host on my linux machine was just fine. So I am inclined to leave it at that. Perhaps we just fix Line 305 (which is in a quote block, more like an "in case it doesn't work .... do this instead"), but leave L297 alone? Thanks for understanding.

[kohashi]

Thanks for the message. I hadn't tried it on a linux machine, but I needed the -p parameters in my Mac environment. I update commit (fix only L305).

[stanley-cheung]

Thanks for the contribution!