DM S20: Make the generals visible during the opening sequence

So the prince can be seen.

data/campaigns/Delfadors_Memoirs/scenarios/20_Prince_of_Wesnoth.cfg

@@ -161,6 +161,16 @@
         [/recall]
         {MODIFY_UNIT (side=1) facing ne}
 
+        # remove fog from the generals so they can be seen during the dialog
+        [lift_fog]
+            [filter_side]
+                side=1
+            [/filter_side]
+            x=34,31
+            y=4,16
+            radius=2
+        [/lift_fog]
+
         [message]
             id=Kalenz
             message= _ "Generals of Wesnoth: you have attacked defenseless elvish land. You must leave immediately. I am Kalenz, High Lord of the Elves. Delfador the Great will confirm the treaty between us."