ospfd: Fix ospfd crash

ospfd: Fix ospfd crash

 - ospfd/ospf_opaque.c: Update issue #1652 by introducing a new
function 'free_opaque_info_owner()' to clean list of callback owner
and call this function in appropriate place where 'listdelete_and_null'
is not used.

 - ospfd/ospf_packet.c: In case of crash, ospfd is not been able to
flush LSA. In case of self Opaque LSA, when restarting, ospfd crash
during the resynchronisation process with its neighbor due to an
empty list of LSA to flood. Just add a control on the list count
in 'ospf_ls_upd_queue_send()' to escape the function and avoid the
problem.

Signed-off-by: Olivier Dugeon <olivier.dugeon@orange.com>