Update LiquidCrystal_I2C.h

Author: joaopedrosgs

LiquidCrystal_I2C.h

@@ -129,6 +129,7 @@ class LiquidCrystal_I2C : public Print {
 	void shiftDecrement();
 	void noBacklight();
 	void backlight();
+	bool getBacklight();
 	void autoscroll();
 	void noAutoscroll();
 	void createChar(uint8_t, uint8_t[]);