Removed Threading in ExecutionTimeSubject because of JavaFX Thread problem

src/main/java/fabrik/simulator/pic16f84/Controller_Frontend.java

@@ -566,6 +566,7 @@ public class Controller_Frontend extends PICComponent implements FrontendControl
     @Override
     public void initialize(PICComponentLocator locator) {
         super.initialize(locator);
+        executionTime.registerObserver(this);
         this.picComponents = locator;
         System.out.println("Frontend");
     }