bring_forward on recieved other instance msg

src/slic3r/GUI/InstanceCheckMac.mm

@@ -19,6 +19,7 @@
 
 -(void)message_update:(NSNotification *)msg
 {
+	[self bring_forward];
 	//pass message  
 	Slic3r::GUI::wxGetApp().other_instance_message_handler()->handle_message(std::string([msg.userInfo[@"data"] UTF8String]));
 }