only start thread for mine being set to active

src/engine/objects/Mine.java

@@ -575,9 +575,11 @@ public class Mine extends AbstractGameObject {
         if (building != null && !this.isActive)
             building.isDeranking.compareAndSet(true, false);
 
-        Thread zergMechanicThread = new Thread(new ZergMechanicThread(null, this));
-        zergMechanicThread.setName(this.zoneName + "Mine");
-        zergMechanicThread.start();
+        if(isAc) {
+            Thread zergMechanicThread = new Thread(new ZergMechanicThread(null, this));
+            zergMechanicThread.setName(this.zoneName + "Mine");
+            zergMechanicThread.start();
+        }
     }
 
     public boolean validForMine(Resource r) {