[HCSR501] Update sensor only on change (#1846)

Improve performance by avoiding unnecessary calls to handleJsonEnqueue when the HCSR501 sensor's state did not change

main/ZsensorHCSR501.ino

@@ -64,8 +64,10 @@ void MeasureHCSR501() {
 #  ifdef HCSR501_LED_NOTIFY_GPIO
     digitalWrite(HCSR501_LED_NOTIFY_GPIO, pirState == HCSR501_LED_ON);
 #  endif
+    if (HCSR501data.size() > 1) {
       HCSR501data["origin"] = subjectHCSR501toMQTT;
       handleJsonEnqueue(HCSR501data);
     }
   }
+}
 #endif