fix error not simulating when unpowered breadboard

Author: kghs-aver

ArduinoFrontend/src/app/Libs/Utils.ts

@@ -183,7 +183,7 @@ export class Utils {
   };
   static checkShortCircuit() {
     const powerConnections = BreadBoard.checkBreadboardPowerConnections();
-    if (BreadBoard.checkAllPinsConnectedToOneRail(powerConnections.poweredRail)) {
+    if (powerConnections.poweredRail != null && BreadBoard.checkAllPinsConnectedToOneRail(powerConnections.poweredRail)) {
       return true;
     } else {
       return false;