[dns] flaky integration test: TestNetListen

[cppforlife]

fails 1/200 or so.

=== RUN   TestNetListen
==> Clean up net access endpoint
Running 'kwt net clean-up'...
==> Starting net start in background
==> Wait for forwarding to be ready
Running 'kwt net start --tty'...
==> Clean up net access endpoint
Running 'kwt net clean-up'...
==> Starting net listen in background
==> Wait for forwarding to be ready
Running 'kwt net listen --tty --local localhost:8080 --service kwt-listen-web'...
==> Wait service to be available
Running 'kwt net svc --json'...
==> Test network accessibility to the HTTP service (web) via 'http://kwt-listen-web.kwt-ebdd4cea962bff63254e23bc372ed54f.svc.cluster.local'
listen cmd output: 
04:54:47PM: info: KubeEntryPoint: Creating networking client secret 'kwt-net-ssh-key' in namespace 'kwt-ebdd4cea962bff63254e23bc372ed54f'...
04:54:47PM: info: KubeEntryPoint: Creating networking host secret 'kwt-net-host-key' in namespace 'kwt-ebdd4cea962bff63254e23bc372ed54f'...
04:54:49PM: info: KubeEntryPoint: Creating networking pod 'kwt-net' in namespace 'kwt-ebdd4cea962bff63254e23bc372ed54f'
04:54:49PM: info: KubeEntryPoint: Waiting for networking pod 'kwt-net' in namespace 'kwt-ebdd4cea962bff63254e23bc372ed54f' to start...
04:54:54PM: info: ListenOptions: Forwarding 80->localhost:8080
04:54:54PM: info: ListenOptions: Ready!
04:54:54PM: info: TCPProxy: Started proxy on dummy-addr

==> Terminating net command tailing
==> Clean up net access endpoint
Running 'kwt net clean-up'...
start cmd output: 
04:54:37PM: info: KubeEntryPoint: Creating networking client secret 'kwt-net-ssh-key' in namespace 'default'...
04:54:37PM: info: KubeEntryPoint: Creating networking host secret 'kwt-net-host-key' in namespace 'default'...
04:54:38PM: info: KubeEntryPoint: Creating networking pod 'kwt-net' in namespace 'default'
04:54:38PM: info: KubeEntryPoint: Waiting for networking pod 'kwt-net' in namespace 'default' to start...
04:54:43PM: info: dns.FailoverRecursorPool: Starting with '8.8.8.8:53'
04:54:43PM: info: dns.DomainsMux: Registering cluster.local.->kube-dns
04:54:43PM: info: TCPProxy: Started proxy on 127.0.0.1:41245
04:54:43PM: info: UDPProxy: Started proxy on 127.0.0.1:33397
04:54:43PM: info: dns.Server: Started DNS server on 127.0.0.1:34835 (TCP) and 127.0.0.1:39304 (UDP)
04:54:43PM: info: ForwardingProxy: Forwarding subnets: 10.4.4.20/14, 10.128.0.7/14
04:54:43PM: info: ForwardingProxy: Ready!
04:54:55PM: info: dns.CustomHandler: AAAA:kwt-listen-web.kwt-ebdd4cea962bff63254e23bc372ed54f.svc.cluster.local.: Answering rcode=0 (46.866µs)
04:54:55PM: info: dns.CustomHandler: A:kwt-listen-web.kwt-ebdd4cea962bff63254e23bc372ed54f.svc.cluster.local.: Answering rcode=0 (6.031184ms)
04:54:55PM: info: TCPProxy: Received 10.254.0.182:32946
04:54:55PM: info: KubeEntryPoint: Creating networking client secret 'kwt-net-ssh-key' in namespace 'default'...
04:54:55PM: info: KubeEntryPoint: Creating networking host secret 'kwt-net-host-key' in namespace 'default'...
04:54:57PM: info: KubeEntryPoint: Creating networking pod 'kwt-net' in namespace 'default'
04:54:57PM: info: KubeEntryPoint: Waiting for networking pod 'kwt-net' in namespace 'default' to start...
04:57:12PM: error: TCPProxy: Could not establish remote connection to '10.7.244.158:80': ssh: rejected: connect failed (Connection timed out)

==> Terminating net command tailing
==> Clean up net access endpoint
Running 'kwt net clean-up'...
--- FAIL: TestNetListen (161.78s)
	network_probe.go:38: Error making HTTP request: Get http://kwt-listen-web.kwt-ebdd4cea962bff63254e23bc372ed54f.svc.cluster.local: read tcp 10.254.0.182:32946->10.7.244.158:80: read: connection reset by peer