Fix bug where ci_job_live_trace_enabled setting has no effect

This change fixes a bug where the wrong configuration option was being set when updating GitLab application settings. Previously, when someone tried to enable or disable live trace logging for CI jobs, the code was mistakenly updating a completely different setting related to namespace plans instead of the intended live trace setting. The fix ensures that changes to the live trace feature now correctly update the right configuration option.

Fixes #6805 (closed)