UtBS S05: Use enter_hex so events cannot be triggered out-of-sequence

Fix #8190

data/campaigns/Under_the_Burning_Suns/scenarios/05_A_Subterranean_Struggle.cfg

@@ -583,7 +583,7 @@
     # Event 1: Spider and Ants
 
     [event]
-        name=moveto
+        name=enter_hex
 
         [filter]
             x=12-18
@@ -663,10 +663,10 @@
     # If player escapes cave spider, then reward player by killing it
 
     [event]
-        name=moveto
+        name=enter_hex
 
         [filter]
-            x=18-24
+            x=20
             y=26-29
             side=1
         [/filter]
@@ -698,11 +698,11 @@
     # When player approaches large cavern, a dying dwarf runs out and yells a warning.
 
     [event]
-        name=moveto
+        name=enter_hex
 
         [filter]
-            x=18-24
-            y=26-28
+            x=20
+            y=26-29
             side=1
         [/filter]