Investigate CTDB tickle ack disconnect behavior on connected smbclient sessions (e.g. in RHGS)

[gd]

When testing this with smbclient and a 6 node RHGS cluster where one node is rebooted (via libvirt), then the session fails with NT_STATUS_CONNECTION_DISCONNECTED (as there is a regular SMB echo ping done), the tickle is sent but it seems not reacted upon.