Jenkins builds fail with WebSocketHandshakeException

As it can be seen at https://ci.eclipse.org/linuxtools/job/linuxtools/job/PR-93/ builds fail with:

Failed to start websocket connection: io.fabric8.kubernetes.client.KubernetesClientException: An error has occurred.
io.fabric8.kubernetes.client.http.WebSocketHandshakeException
	at io.fabric8.kubernetes.client.okhttp.OkHttpWebSocketImpl$BuilderImpl$1.onFailure(OkHttpWebSocketImpl.java:66)
	at okhttp3.internal.ws.RealWebSocket.failWebSocket(RealWebSocket.java:571)
	at okhttp3.internal.ws.RealWebSocket$2.onResponse(RealWebSocket.java:198)

This happened in other PR too https://ci.eclipse.org/linuxtools/job/linuxtools/view/change-requests/job/PR-92/1/console .