EI items: add [filter_second] to Sentinel Shield and set delay=0 (#8984)

Delay=0 fixes an annoying animation issue, as the default is delay=500.

data/campaigns/Eastern_Invasion/utils/items.cfg

@@ -439,6 +439,9 @@ sentinel #enddef
                 is_enemy=no
             [/filter_adjacent]
         [/filter]
+        [filter_second]
+            id=${ATTACKER}.id
+        [/filter_second]
 
         amount=$sentinel_damage
         damage_type=${WEAPON}.type
@@ -446,6 +449,7 @@ sentinel #enddef
         poisoned=$sentinel_poisons
         slowed=$sentinel_slows
         animate=yes
+        delay=0
         fire_event=yes
         #         variable=sentinel_damage_dealt # this throws an error if the unit dies. Instead, base drain_amount on $sentinel_damage, regardless of resistances
     [/harm_unit]