Fix incorrect Prevent Action special nodes in the scenarios, caused by incorrect import code

The fix was implemented by re-importing the legacy scenarios and re-exporting them,
then simply accepting any changes to a Prevent Action node.

rsrc/scenarios/valleydy/towns/town15.spec

@@ -9,7 +9,7 @@
 	sdf -1, -1
 	msg -1, -1, -1
 	pic 0, 4
-	ex1 0, -1, -1
+	ex1 1, -1, -1
 	ex2 0, -1, -1
 	goto -1
 @damage = 2
@@ -23,7 +23,7 @@
 	sdf -1, -1
 	msg 7, 8, -1
 	pic 0, 4
-	ex1 0, -1, -1
+	ex1 1, -1, -1
 	ex2 0, -1, -1
 	goto -1
 @stair = 4