Description:

Fixes #20713

This PR simply removes the code which modifies the X-FORWARDED-FOR header with the current user IP address in the HTTP class which prevents the unintentional leaking of the user IP to plugins.matomo.org, After analyzing the reason this code was originally added it was determined that it was incorrect to consider Matomo a proxy in this case and that any issues with outbound proxies should be solved at network and not application level.

A breaking change note is included in changelog.md to warn anyone using this header for outbound proxies that they may need to update their rules.

Review

• Functional review done
• Potential edge cases thought about (behavior of the code with strange input, with strange internal state or possible interactions with other Matomo subsystems)
• Usability review done (is anything maybe unclear or think about anything that would cause people to reach out to support)
• Security review done
• Wording review done
• Code review done
• Tests were added if useful/possible
• Reviewed for breaking changes
• Developer changelog updated if needed
• Documentation added if needed
• Existing documentation updated if needed