Serve correct TLS certificate for requests with uppercase host

[AndiDog]

What this PR does / why we need it:

Follow-up to #5456 which didn't fully solve the problem. This time, I was able to test the full flow by editing a Lua script and trying an uppercase-host request like curl -kv https://MY-UPPERCASE-HOST/.

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)

How Has This Been Tested?

Edited 0.32.0 controller image with this one-line change and saw that a request with uppercase host provides the TLS certificate specified in the Ingress object instead of falling back to the fake default certificate.

Unfortunately I don't have a good idea how to test it, since there's no example test requesting /configuration/servers or similar.

Checklist:

• My change requires a change to the documentation.
• I have updated the documentation accordingly.
• I've read the CONTRIBUTION guide
• I have added tests to cover my changes.
• All new and existing tests passed.

[k8s-ci-robot]

Hi @AndiDog. Thanks for your PR.

I'm waiting for a kubernetes member to verify that this patch is reasonable to test. If it is, they should reply with /ok-to-test on its own line. Until that is done, I will not automatically test new commits in this PR, but the usual testing commands by org members will still work. Regular contributors should join the org to skip this step.

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[aledbf]

/ok-to-test

[aledbf]

/assign @ElvinEfendi

[aledbf]

/retest

[aledbf]

/retest

[aledbf]

/lgtm
/approve

[aledbf]

@AndiDog thanks!

[k8s-ci-robot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: aledbf, AndiDog

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[k8s-ci-robot]

@AndiDog: The following tests failed, say /retest to rerun all failed tests:

Test name	Commit	Details	Rerun command
pull-ingress-nginx-lualint	ab024c6	link	/test pull-ingress-nginx-lualint
pull-ingress-nginx-e2e-1-16	ab024c6	link	/test pull-ingress-nginx-e2e-1-16

Full PR test history. Your PR dashboard. Please help us cut down on flakes by linking to an open issue when you hit one in your PR.

Instructions for interacting with me using PR comments are available here. If you have questions or suggestions related to my behavior, please file an issue against the kubernetes/test-infra repository. I understand the commands that are listed here.

[aledbf]

Merging. I will fix the lualint issue in a new PR