Fix interdiction not to wipe out target ship updates
Ships can expend shells to defend against missiles, in
shp_missile_defense(). Any shell use by the target ship got wiped out
when shp_missile_interdiction() wrote back the target ship, triggering
a seqno mismatch oops.
Ships get updated when they launch planes to intercept interdicting
planes, in mission_pln_equip(). Any petrol use by the target ship got
wiped out when shp_mission_interdiction() wrote back the target ship,
triggering a seqno mismatch oops.
Fix by re-reading the target ship in shp_damage_one(). This also
affects shp_fort_interdiction(), where it is not necessary. A bit
inefficient, but let's keep this fix simple.
(cherry picked from commit
1d4fea32b845686163b9be79e21ca7ea279357e1)