[ajax] fix the fix introduced in 3.9.1 to avoid duplicated loads: it cause some other errors since the browser may load the script *after* the server-response event is emited, causing pb if the script interact with this event

function set_tab(tabname, cookiename) {
    // set appropriate cookie
    loadRemote('json', ajaxFuncArgs('set_cookie', null, cookiename, tabname));
    // trigger show + tabname event
    trigger_load(tabname);
}