Formatter Fixed A Crash Bug In The Requested

Fix: CVE-2026-47220 <https://github.com/envoyproxy/envoy/security/advisories/GHSA-j9wh-4qfm-wf2v>_

Fixed a crash bug in the %REQUESTED_SERVER_NAME% formatter where the host or original host is not set correctly but the formatter is configured to access the host value.