do not leak LB when ingress class is changed

[agadelshin]

This PR fixes #481

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[k8s-ci-robot]

Hi @pondohva. 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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[agadelshin]

@rramkumar1 excuse me, should I do smth to re-run CLA check? I fixed email in commit.

[rramkumar1]

/ok-to-test

[agadelshin]

/assign @rramkumar1

please look at this

[rramkumar1]

@pondohva Sorry for the delay. I will try to have another review by EOD

[rramkumar1]

@pondohva This looks good to me. Can you please add a unit test?

Once you add the test, I will merge this.

[agadelshin]

@rramkumar1 could you please check test and wrapper function?

[rramkumar1]

Couple nits.

Once these are fixed, will merge this.

[agadelshin]

@rramkumar1 Thank you for feedback. All nits were fixed.

[rramkumar1]

/lgtm

[k8s-ci-robot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: pondohva, rramkumar1

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