I am using below code for sample menu.
Tree Demo
That's something I'm not sure that you can change through the HTML of the webpage itself, it's a client-side setting to tell their browser if they want security to be high. Most other browsers will not do this but from what I'm aware of this is not possible to stop unless the user disables the feature.
Does it still do what you want it to do after you click on 'Allow'? If so then it shouldn't be too much of a problem