ssa.c: Eliminate closing listen rsockets

If SMDB / PRDB listen rsockets are closed on port error
event, in case of port bouncing or handover back, later
on those sockets won't be opened properly (due to some
librdma library limitation) so no distribution node will
be available to connect to it.

Signed-off-by: Ilya Nelkenbaum <ilyan@mellanox.com>