Clean up the firewall manager check for if it is enabled. Now it returns almost instantly instead of waiting for a few seconds.

src/server/library/sysadm-firewall.cpp

@@ -148,8 +148,7 @@ bool Firewall::IsRunning()
 }
 
 bool Firewall::IsEnabled(){
-    ServiceManager serviceManager;
-    return serviceManager.isEnabled( serviceManager.GetService("ipfw") );
+  return (0 == system("sysrc -c firewall_enable=\"YES\"") );
 }
 
 void Firewall::Start()