NR 07a: Properly store the gold for later and give intended starting gold

Otherwise, gold is not stored to be recovered for S13a and player is given
100 gold for starting S07a no matter the difficulty.

[ci skip]

data/campaigns/Northern_Rebirth/scenarios/07a_Settling_Disputes.cfg

@@ -125,7 +125,7 @@
         side=1
         controller=human
         recruit=Peasant,Woodsman,Thug,Poacher,Spearman,Bowman,Footpad
-        {GOLD 200 100 80}
+        gold=0 #player has large carryover here, is handled in prestart event
         team_name=knalgans
         user_team_name= _ "Knalgans"
 
@@ -278,10 +278,14 @@
     [event]
         name=prestart
 
-        # Remove players gold and give him initial 100
+        # Store player's carryover gold and give him initial starting gold
+        [store_gold]
+            side=1
+            variable=stored_gold
+        [/store_gold]
         [modify_side]
             side=1
-            gold=100
+            {GOLD 200 100 80}
         [/modify_side]
 
         # Recall heroes