Change all addresses to be relative

core/css/tabbed-container.css

@@ -79,7 +79,7 @@
 	display: inline-block;
 	width: 16px; height: 16px;
 	margin-left: 4px;
-	background-image: url('//assets.worlio.com/style/icons/close');
+	background-image: url('icons/close');
 	background-size: 100%;
 	cursor: pointer;
 }