rework IsLocalIP using standard library functions

[r41d]

• don't hardcode IPs but rather use the standard library for checking loopback and private networks
• one of the old checks with strings.HasPrefix(ip, "172.") was too broad because the private range is 172.16/12 and not 172/8
• addtional private networks are added

[cla-bot]

We require contributors to sign our Contributor License Agreement. In order for us to review and merge your code, add yourself to the .clabot file as contributor, as a way of signing the CLA.

[cla-bot]

We require contributors to sign our Contributor License Agreement. In order for us to review and merge your code, add yourself to the .clabot file as contributor, as a way of signing the CLA.

[r41d]

Hmm, the bot seems to fetch the .clabot file from the original repo and not my branch 🤔

[r41d]

Any feedback or something that could be done better?

[azukaar]

Hey Thanks for the PR, upon merging it I realized that you created a PR against Master instead of unstable, could you redirect it?
dont worry about cla bot he is a lilttle... slow :p

[r41d]

Hey Thanks for the PR, upon merging it I realized that you created a PR against Master instead of unstable, could you redirect it? dont worry about cla bot he is a lilttle... slow :p

Done :)
#364

[azukaar]

Thanks!!