Automatic merge from submit-queue
kubeadm: Remove an outdated comment
Now that `AdvertiseAddress` is a `string` and not
`AdvertiseAddresses` a `[]string` this comment is no longer
necessary.
@k8s-mirror-cluster-lifecycle-misc RFR
**What this PR does / why we need it**
Just a little house cleaning by removing an outdated comment.
**Release note**:
```release-note
NONE
```