fix event var

src/Temperature.cpp

@@ -20,7 +20,7 @@ double Temperature::getTemp() {
 }
 
 double Temperature::getHum() {
-    // Get humidity event and print its value.
+    sensors_event_t event;
     dht.humidity().getEvent(&event);
     if (isnan(event.relative_humidity)) {
         return -1;