fix a bug that couldn't set the right fcu gear

app/controllers/equipment/fcu.py

@@ -29,8 +29,7 @@ class FCUController(EquipmentController):
     async def get_air_valve_speed(self):
         temperature_target = await self.get_temperature_target()
         if temperature_target > 0:
-            # self._equipment.air_valve_speed = AirValveSpeed.auto
-            diff = temperature_target - self._equipment.space.realtime_temperature
+            diff = self._equipment.space.realtime_temperature - temperature_target
             if diff >= 2.0:
                 self._equipment.air_valve_speed = AirValveSpeed.high
             elif diff >= 1.0: