Problem with HTTP/HTTPS in header

Hello, my site have a problem with header. In HTML of my site (www.staipa.it) it appear this CSS

<style type="text/css" rel="header-image">
			.custom-header:before {
				background-image: url( http://1);
				background-position: center top;
				background-repeat: no-repeat;
				background-size: cover;
			}
		</style>

It cause problem with SSL certificate in Edge Chromium, because it interpret that stil searching to download a file from http://0.0.0.1 withot HTTPS. Problem is in theme because if I change theme problem disappear. How can I do for solve?