Fix ObserverTracer

Signed-off-by: yoyosource <yoyosource@nidido.de>

BauSystem_Main/src/de/steamwar/bausystem/features/observer/ObserverTracer.java

@@ -95,6 +95,9 @@ public class ObserverTracer {
                 calculateSpecial(b);
             }
 
+            if (b.getType() == Material.OBSERVER) {
+                continue;
+            }
             if (b.getType().isBlock() && b.getType().isSolid() && b.getType().isOccluding()) {
                 calculateSolidBlock(b);
             }