Disable double submission in login form

[fmido88]

I added the code

   require(['core_form/submit'], function(Submit) {
    Submit.init("loginbtn");
    {{#canloginasguest}}
        Submit.init("loginguestbtn");
    {{/canloginasguest}}
});

To the js code in the file login.mustache
As in the loginform.mustache in the core templates
It solved the problem of invalid login due to double submission

I hope to add it in the next update
Thanks