Summary:
Commit 0fee13f1cc17f10a035d87f6fcaec3577c041752 broke the gcc12 build which is used by GitHub actions as a post-commit check. This diff fixes the compilation of gcc12 by not reading from a std::optional unconditionally.
Jira: DB-15911

Test Plan:
Build on dev-server with gcc12 to validate fix: `./yb_build.sh --gcc12 --with-tests`
Jenkins: urgent compile only

Reviewers: hsunder

Reviewed By: hsunder

Subscribers: ybase

Differential Revision: https://phorge.dev.yugabyte.com/D42794