Fix internal sub-request creation

Fixes the creation of internal sub-request in case of disabled trusted
client-ip header
merged branch lazyhammer/fix-inline-fragment (PR #7893)

This PR was submitted for the master branch but it was merged into the 2.3 branch instead (closes #7893).

Discussion
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[HttpKernel] Fix internal sub-request creation

| Q             | A
| ------------- | ---
| Bug fix?      | yes
| New feature?  | no
| BC breaks?    | no
| Deprecations? | no
| Tests pass?   | yes
| Fixed tickets | n/a
| License       | MIT
| Doc PR        | n/a

Fixes the creation of internal sub-request in case of disabled trusted
client-ip header.

Commits
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85d5413 [HttpKernel] Fix internal sub-request creation