MoveScore: nicht-existente EK abfangen.

Change-Id: Ia81ebbfb6450a3ab0485e905e92f7d290b0e6119
diff --git a/secure/scoremaster.c b/secure/scoremaster.c
index 0cd1e5d..83dc466 100644
--- a/secure/scoremaster.c
+++ b/secure/scoremaster.c
@@ -651,7 +651,10 @@
 
   if (stringp(oldkey)) {
     oldkey = load_name(oldkey); 
-    num=npcs[oldkey,NPC_NUMBER];
+    if (member(npcs, oldkey))
+      num=npcs[oldkey,NPC_NUMBER];
+    else
+      return SCORE_INVALID_ARG;
   }
   else if (intp(oldkey)) num=oldkey;
   else return SCORE_INVALID_ARG;