safekeeper: Fix a log message of HTTP worker

[shinyaaa]

Problem

There is a wrong log message.

Summary of changes

Fixed the log message.

Checklist before requesting a review

• I have performed a self-review of my code.
• If it is a core feature, I have added thorough tests.
• Do we need to implement analytics? if so did you add the relevant metrics to the dashboard?
• If this PR requires public announcement, mark it with /release-notes label and add several sentences in this section.

Checklist before merging

• Do not forget to reformat commit message to not include the above checklist

[github-actions]

5022 tests run: 4864 passed, 0 failed, 158 skipped (full report)

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Flaky tests (1)

Postgres 17

• test_ondemand_wal_download_in_replication_slot_funcs: release-x86-64

Code coverage* (full report)

• functions: 31.3% (7489 of 23904 functions)
• lines: 49.6% (60095 of 121237 lines)

* collected from Rust tests only

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_{The comment gets automatically updated with the latest test results
610ee7b at 2024-10-01T15:08:59.463Z :recycle:}