EI S8: Fix event not being fired

The second event took as filtered unit an ogre that has reached
the border of the map. Unfortunately, he was removed by the map
before such event was fired, causing it to never happen.

data/campaigns/Eastern_Invasion/scenarios/08_Training_the_Ogres.cfg

@@ -186,17 +186,14 @@
         [/kill]
 
         {CLEAR_VARIABLE ogre_escape_msgs}
+
+        [fire_event]
+            name=first ogre escapes
+        [/fire_event]
     [/event]
 
     [event]
-        name=moveto
-
-        [filter]
-            race=ogre
-            [filter_location]
-                {MAP_EDGES_SLF}
-            [/filter_location]
-        [/filter]
+        name=first ogre escapes
 
         [message]
             speaker=Gweddry