Fix wall blocking exit

There is supposed to be an exit that opens when you take the cloak of
magic resistance, but a wall is blocking it.

pup_land/ancient/castle/castle.6

@@ -8,7 +8,7 @@ enter_x 24
 enter_y 24
 msg
 Created: 1996-12-15
-Modified: 2023-06-09 Rick Tanner
+Modified: 2024-03-22 Kevin Zheng
 endmsg
 end
 arch marble
@@ -4243,22 +4243,18 @@ end
 arch marble
 x 13
 end
-arch cwall_3_3
+arch cwall_2_1_2
 x 13
 end
 arch marble
 x 13
 y 1
 end
-arch cwall_3_4
-x 13
-y 1
-end
 arch marble
 x 13
 y 2
 end
-arch cwall_4
+arch cwall_3_3
 x 13
 y 2
 end