CJ125 heater zero PWM improvement

firmware/controllers/system/pwm_generator_logic.cpp

@@ -75,7 +75,7 @@ void SimplePwm::setSimplePwmDutyCycle(float dutyCycle) {
 		warning(CUSTOM_ERR_6579, "spwd:dutyCycle %.2f", dutyCycle);
 		return;
 	}
-	if (dutyCycle == 0.0f) {
+	if (dutyCycle == 0.0f && stateChangeCallback != NULL) {
 		/**
 		 * set the pin low just to be super sure
 		 * this custom handling of zero value comes from CJ125 heater code

firmware/controllers/system/pwm_generator_logic.h

@@ -96,7 +96,7 @@ public:
 	/**
 	 * this main callback is invoked when it's time to switch level on any of the output channels
 	 */
-	pwm_gen_callback *stateChangeCallback;
+	pwm_gen_callback *stateChangeCallback = NULL;
 private:
 	/**
 	 * float value of PWM period