Correct reactive power device class (#1417)

* reactive power

* fix

* exclude energy reactive

custom_components/ocpp/sensor.py

@@ -156,15 +156,19 @@ def device_class(self):
             device_class = SensorDeviceClass.CURRENT
         elif self.metric.lower().startswith("voltage"):
             device_class = SensorDeviceClass.VOLTAGE
+        elif self.metric.lower().startswith("energy.r"):
+            device_class = None
         elif self.metric.lower().startswith("energy."):
             device_class = SensorDeviceClass.ENERGY
         elif self.metric in [
             Measurand.frequency,
             Measurand.rpm,
         ] or self.metric.lower().startswith("frequency"):
             device_class = SensorDeviceClass.FREQUENCY
-        elif self.metric.lower().startswith(("power.a", "power.o", "power.r")):
+        elif self.metric.lower().startswith(("power.a", "power.o")):
             device_class = SensorDeviceClass.POWER
+        elif self.metric.lower().startswith("power.r"):
+            device_class = SensorDeviceClass.REACTIVE_POWER
         elif self.metric.lower().startswith("temperature."):
             device_class = SensorDeviceClass.TEMPERATURE
         elif self.metric.lower().startswith("timestamp.") or self.metric in [