Simple Attack MAI test scenario: move Lua filter function into preload event

… so that it is available after a reload as well.

data/ai/micro_ais/scenarios/simple_attack.cfg

@@ -46,6 +46,22 @@
         hidden=yes
     [/side]
 
+    [event]
+        name=preload
+        first_time_only=no
+        [lua]
+            code=<<
+                function close_to_advancing(unit)
+                    if (unit.experience >= unit.max_experience-1) then
+                        return true
+                    else
+                        return false
+                    end
+                end
+            >>
+        [/lua]
+    [/event]
+
     [event]
         name=prestart
 
@@ -64,18 +80,6 @@
         {SCATTER_UNITS 12 "Soulless" 1 (x,y=5-9,8-22) (side=2)}
         {SCATTER_UNITS 6 "Skeleton,Skeleton Archer" 1 (x,y=5-9,8-22) (side=2)}
 
-        [lua]
-            code=<<
-                function close_to_advancing(unit)
-                    if (unit.experience >= unit.max_experience-1) then
-                        return true
-                    else
-                        return false
-                    end
-                end
-            >>
-        [/lua]
-
         [micro_ai]
             side=2
             ai_type=simple_attack