Fixed sim808 components power state not being detected in case of an error

GpsTracker/Hardware.cpp

@@ -28,8 +28,8 @@ namespace hardware {
 		void powerOffIfUnused() {
 			bool gpsPowered = false;
 			bool gprsPowered = false;
-			if ((device.getGpsPowerState(&gpsPowered) && !gpsPowered) &&
-				(device.getGprsPowerState(&gprsPowered) && !gprsPowered)) {
+			if ((!device.getGpsPowerState(&gpsPowered) || !gpsPowered) &&
+				(!device.getGprsPowerState(&gprsPowered) || !gprsPowered)) {
 				powerOff();
 			}
 		}