Fix false-positive code scanning issue

[jjngx]

Proposed changes

This PR, if merged, will fix false-positive code scanning issues. The var names with prefixes "secret" are recognised by the scanner as secrets (passed to logs).

scanning issues:

• https://github.com/nginxinc/kubernetes-ingress/security/code-scanning/10543
• https://github.com/nginxinc/kubernetes-ingress/security/code-scanning/10542

Checklist

Before creating a PR, run through this checklist and mark each as complete.

• I have read the CONTRIBUTING doc
• I have added tests that prove my fix is effective or that my feature works
• I have checked that all unit tests pass after adding my changes
• I have updated necessary documentation
• I have rebased my branch onto main
• I will ensure my PR is targeting the main branch and pulling from my branch from my own fork