Update the unspecified IP blocking documentation

[farcaller]

By submitting this pull request, I confirm the following: please fill any appropriate checkboxes, e.g: [X]

• [x] I have read and understood the contributors guide, as well as this entire template.
• [x] I have made only one major change in my proposed changes.
• [x] I have commented my proposed changes within the code.
• [x] I have tested my proposed changes, and have included unit tests where possible.
• [x] I am willing to help maintain this change if there are issues with it later.
• [x] I give this submission freely and claim no ownership.
• [x] It is compatible with the EUPL 1.2 license
• [x] I have squashed any insignificant commits. (git rebase)

Please make sure you Sign Off all commits. Pi-hole enforces the DCO.

---

What does this PR aim to accomplish?: Update the documentation reflecting 0.0.0.0 being treated like 127.0.0.1 in some cases. This behavior can trigger in a bunch of networking stacks, e.g. Zoom on macOS will try to connect to a local webserver if some zoom urls are blocked. Similarly, most of Synology's software running on Linux will try to do the same.

---

• You must follow the template instructions. Failure to do so will result in your pull request being closed.
• Please respect that Pi-hole is developed by volunteers, who can only reply in their spare time.

[netlify[bot]]

✅ Deploy Preview for pihole-docs ready!

Name	Link
🔨 Latest commit	1dbb7f4f3c16685e5e8a11a4a3a980c081e1cb0b
🔍 Latest deploy log	https://app.netlify.com/sites/pihole-docs/deploys/624ea1bc947c0d0008c57e3c
😎 Deploy Preview	https://deploy-preview-687--pihole-docs.netlify.app/ftldns/blockingmode
📱 Preview on mobile	Toggle QR Code... Use your smartphone camera to open QR code link.

---

To edit notification comments on pull requests, go to your Netlify site settings.

[netlify[bot]]

✅ Deploy Preview for pihole-docs ready!

Name	Link
🔨 Latest commit	5c376121aded3ae2b10166efb53518734df105ed
🔍 Latest deploy log	https://app.netlify.com/sites/pihole-docs/deploys/62f8c73f1f2f640009f7f1eb
😎 Deploy Preview	https://deploy-preview-687--pihole-docs.netlify.app/ftldns/blockingmode
📱 Preview on mobile	Toggle QR Code... Use your smartphone camera to open QR code link.

---

To edit notification comments on pull requests, go to your Netlify site settings.

[farcaller]

Sorry for the long delay in reviewing. I made two small change suggestions, what do you think? NULL still seems to be the best "universal" solution we have at hand, we shouldn't be too negative about it

Yeah, with a caveat of "depends on your OS" 😄

[github-actions[bot]]

Existing merge conflicts have not been addressed. This PR is considered abandoned.

[farcaller]

derp, it's not like I get email notifications for labels...

[farcaller]

...but it looks like this was already merged in with a similar wording either way, so no point in rebasing.