Rolling duration updated

src/engine/gameManager/ForgeManager.java

@@ -142,7 +142,7 @@ public enum ForgeManager implements Runnable {
 
         float rollingDuration;
 
-        rollingDuration = workOrder.vendor.getBuilding().getRank() * 5L + 40;
+        rollingDuration = workOrder.vendor.getBuilding().getRank() * -5L + 40;
         rollingDuration *= 60000;
         rollingDuration *= Float.parseFloat(ConfigManager.MB_PRODUCTION_RATE.getValue());