Inside your theme's qa-theme.php file, add this function towards the end:
function head_custom() {
qa_html_theme_base::head_custom();
if ($this->template == "YOUR_TEMPLATE" || $this->request == "YOUR_URL") {
$this->output('<style>.qa-notice {display:none !important;}</style>');
}
}
Please note if a head_custom() funtion is already present then you just need to append the contents of above function to it.