Update head.html

Author: Xander8

_includes/head.html

@@ -11,7 +11,7 @@
   <meta name="viewport" content="width=device-width, minimum-scale=1.0, maximum-scale=1.0, user-scalable=no">
   <link rel="icon" href="/favicon.ico" type="image/x-icon" />
 
-  <link rel="stylesheet" href="{{ site.github.url }}/assets/css/style.css">
+  <link rel="stylesheet" href="{//{ site.github.url }}/assets/css/style.css">
   <link href="https://fonts.googleapis.com/css?family=Source+Code+Pro" rel="stylesheet">
 
   <!-- <script type="text/javascript" src="{{ site.github.url }}/assets/js/script.js" async></script> -->