update variable name

config.py

@@ -18,7 +18,7 @@ class ess_config:
 class grid_config:
     def __init__(self, capacity, price_schedule, grid_loss, sell_price):
         self.price_schedule = price_schedule
-        self.grid_loss = grid_loss
+        self.loss = grid_loss
         self.sell_price = sell_price
         self.capacity = capacity