winbind: Retry after SESSION_EXPIRED error in ping-dc

winbind: Retry after SESSION_EXPIRED error in ping-dc

Trying to establish a netlogon connection when the service ticket
expires might fail with NT_STATUS_NETWORK_SESSION_EXPIRED. The
underlying client code already marks the session as invalid, so retry
the netlogon connect in this case.

Signed-off-by: Christof Schmit <cs@samba.org>
Reviewed-by: Jeremy Allison <jra@samba.org>
Autobuild-User(master): Jeremy Allison <jra@samba.org>
Autobuild-Date(master): Tue Jan  6 02:58:57 CET 2015 on sn-devel-104
(cherry picked from commit a2670f15dea27c10e3827216adf572f9c3894f85)

BUG: https://bugzilla.samba.org/show_bug.cgi?id=11034