remove unneeded increment of depth

src/logic/future_moves.rs

@@ -204,7 +204,7 @@ impl FutureMoves {
                     .sum::<i128>();
 
                 self.arena[idx].value =
-                    (self.arena[idx].self_value / (depth as i64 + 1)) as i128 + children_value;
+                    (self.arena[idx].self_value / (depth as i64)) as i128 + children_value;
             }
         }
     }