Standardize praefect docs on using internal ip as address

What does this MR do?

the main gitaly and praefect ports, as well as the gitaly prometheus and praefect prometheus ports are handled by the cloudflare tableflip library, which will refuse to upgrade if a different address is used with the same port. The default in omnibus is localhost. By standardizing to the internal ip for these addresses in the docs, we avoid the problem of having 0.0.0.0 as the address and either gitaly or praefect failing to upgrade.

addresses: gitaly#2521 (closed)

Screenshots

Does this MR meet the acceptance criteria?

Conformity

• Changelog entry
• Documentation (if required)
• Code review guidelines
• Merge request performance guidelines
• Style guides
• Database guides
• Separation of EE specific content

Availability and Testing

• Review and add/update tests for this feature/bug. Consider all test levels. See the Test Planning Process.
• Tested in all supported browsers
• Informed Infrastructure department of a default or new setting change, if applicable per definition of done

Security

If this MR contains changes to processing or storing of credentials or tokens, authorization and authentication methods and other items described in the security review guidelines:

• Label as security and @ mention @gitlab-com/gl-security/appsec
• The MR includes necessary changes to maintain consistency between UI, API, email, or other methods
• Security reports checked/validated by a reviewer from the AppSec team