Small fix in ZITrader demo

Author: thiagowinkler

demo/zitrader.py

@@ -177,6 +177,9 @@ def main(argv: List[str]):
             )
             if verbose:
                 print(f"Bid Size: {order_size}")
+            if order_size == 0:
+                print(f"Not submitting order of size: : {order_size}")
+                continue
 
             limit_buy = shift.Order(
                 shift.Order.Type.LIMIT_BUY, stock_ticker, order_size, order_price
@@ -209,6 +212,9 @@ def main(argv: List[str]):
             )
             if verbose:
                 print(f"Ask Size: {order_size}")
+            if order_size == 0:
+                print(f"Not submitting order of size: : {order_size}")
+                continue
 
             limit_sell = shift.Order(
                 shift.Order.Type.LIMIT_SELL, stock_ticker, order_size, order_price