Fixed typo

Boiler.h

-//
-// Created by robin on 1/27/20.
-//
-
-#ifndef HEATER_BOILER_H
-#define HEATER_BOILER_H
+#pragma once
 
 typedef char temp_t;
 typedef unsigned long timestamp_t;
     AppState appState;
     UiState uiState;
 };
-
-#endif //HEATER_BOILER_H