This disables by default (if not specified in the machine config) the endpoint harvesting for KubeSpan peers. The idea was to observe Wireguard endpoints as seen by other peers in the cluster, and add them to the list of endpoints for the node. This might be helpful only in case of some special type of NATs which are almost never seen in the wild today. So disable by default, but keep an option to enable it. Signed-off-by: Andrey Smirnov <andrey.smirnov@siderolabs.com>