Added information what http server listen on

[csakshaug]

Description

Give information where the HTTP server listen on

Motivation and Context

It is not information where http port is listen, like the metrics server.

• [x] I have raised an issue to propose this change ([required]

https://github.com/openfaas-incubator/of-watchdog/issues/67

How Has This Been Tested?

Just execute it and see that output is correct

Types of changes

• [ ] Bug fix (non-breaking change which fixes an issue)
• [x] New feature (non-breaking change which adds functionality)
• [ ] Breaking change (fix or feature that would cause existing functionality to change)

Checklist:

• [ ] My code follows the code style of this project.
• [ ] My change requires a change to the documentation.
• [ ] I have updated the documentation accordingly.
• [x] I've read the CONTRIBUTION guide
• [ ] I have signed-off my commits with git commit -s
• [ ] I have added tests to cover my changes.
• [ ] All new and existing tests passed.

[derek[bot]]

Thank you for your contribution. I've just checked and your commit doesn't appear to be signed-off. That's something we need before your Pull Request can be merged. Please see our contributing guide. Tip: if you only have one commit so far then run: git commit --amend --signoff and then git push --force.

[alexellis]

@csakshaug please can you try as per above?

[alexellis]

Thanks, for your first PR! :tada: You may now appear on openfaas.com as one of our contributors!