AToTB S01 Fix bug: No unit for role

Include all possible advancements, but exclude Arvith, and recruit a replacement if no unit found.

data/campaigns/Two_Brothers/scenarios/01_Rooting_Out_a_Mage.cfg

@@ -290,8 +290,20 @@ Will he heed the call? I do not know if he has kept the amulet; we have not spok
         [/message]
 
         [role]
-            type=Spearman,Bowman,Horseman
+            type="Royal Guard,Halberdier,Master Bowman,Paladin,Grand Knight,Fugitive," +
+                 "Swordsman,Pikeman,Javelineer,Longbowman,Knight,Lancer,Outlaw," +
+                 "Spearman,Bowman,Horseman,Footpad"
             role=Reporter
+            [not]
+                id=Arvith
+            [/not]
+            [else]
+                [unit]
+                    role=Reporter
+                    type=Spearman
+                    placement=leader
+                [/unit]
+            [/else]
         [/role]
 
         [message]