SotBE S2: ensure that there is a helper unit at Turn 7

... even if all player units have been killed by then (except for maybe
Vrag).

data/campaigns/Son_Of_The_Black_Eye/scenarios/02_The_Human_Army.cfg

@@ -146,6 +146,17 @@
             x=1-99
         [/role]
 
+        [if]
+            [not]
+                [have_unit]
+                    role=Helper
+                [/have_unit]
+            [/not]
+            [then]
+                {UNIT 1 (Orcish Grunt) 16 3 (role=Helper)}
+            [/then]
+        [/if]
+
         [if]
             [have_unit]
                 id=Vrag