Merge pull request #1829 from 1122455801/bitmex_0614

[Mod] bitmex_gateway增加持仓推送过滤

vnpy/gateway/bitmex/bitmex_gateway.py

@@ -661,6 +661,9 @@ class BitmexWebsocketApi(WebsocketClient):
 
     def on_position(self, d):
         """"""
+        if not d["currentQty"]:
+            return
+
         position = PositionData(
             symbol=d["symbol"],
             exchange=Exchange.BITMEX,