Fix units stuck in spider wall and filter

(cherry picked from commit eb123ed8bb)

data/campaigns/Northern_Rebirth/scenarios/05a_01_The_Pursuit.cfg

@@ -1689,8 +1689,8 @@
         name=moveto
         [filter]
             side=1
-            x=10-18
-            y=1-6
+            x=10-18,11-17
+            y=1-6,7
         [/filter]
 
         [scroll_to]
@@ -1725,6 +1725,40 @@
             terrain=Xu
         [/terrain]
 
+        # When cutting off the exit, test for units on the wall, if there are units on the wall, teleport them back
+
+        [if]
+            [have_unit]
+                side=1
+                x=9,7
+            [/have_unit]
+            [then]
+                [teleport]
+                    [filter]
+                        x,y=9,7
+                    [/filter]
+                    x,y=10,7
+                    check_passability=yes
+                [/teleport]
+            [/then]
+        [/if]
+
+        [if]
+            [have_unit]
+                side=1
+                x=10,7
+            [/have_unit]
+            [then]
+                [teleport]
+                    [filter]
+                        x,y=10,7
+                    [/filter]
+                    x,y=9,7
+                    check_passability=yes
+                [/teleport]
+            [/then]
+        [/if]
+
         [redraw][/redraw]
 
         [message]