test(apiserver): deflake TestClientReceivedGOAWAY
test(apiserver): deflake TestClientReceivedGOAWAY

protect `localAddr` from concurrent read and write

Signed-off-by: knight42 <anonymousknight96@gmail.com>

Kubernetes-commit: 1f235c858c39f77161d5b5e8272a7113bfca3143

kubernetes/apiserver,kubernetes/apiserver