Fix Nest interpreting Celsius temperature as Fahrenheit (#4729)

homeassistant/components/climate/nest.py

@@ -229,7 +229,7 @@ class NestThermostat(ClimateDevice):
         self._eco_temperature = self.device.eco_temperature
         self._locked_temperature = self.device.locked_temperature
         self._is_locked = self.device.is_locked
-        if self.device.temperature == 'C':
+        if self.device.temperature_scale == 'C':
             self._temperature_scale = TEMP_CELSIUS
         else:
             self._temperature_scale = TEMP_FAHRENHEIT