Set dynamic base href.

client/src/index.html

@@ -4,6 +4,12 @@
     <meta charset="utf-8" />
     <title>Real-Debrid Torrent Client</title>
     <base href="/" />
+    <script>
+      (function () {
+        window["_app_base"] = "/" + window.location.pathname.split("/")[1];
+        console.log('setting base href to ' + window["_app_base"])
+      })();
+    </script>
     <meta name="viewport" content="width=device-width, initial-scale=1" />
     <link rel="icon" type="image/x-icon" href="favicon.ico" />
   </head>