Make api url configurable in index.html

public/config.json

@@ -1,3 +0,0 @@
-{
-  "VIKUNJA_API_BASE_URL": "http://localhost:8080/api/v1/"
-}

public/index.html

@@ -25,5 +25,13 @@
 </noscript>
 <div id="app"></div>
 <!-- built files will be auto injected -->
+<script>
+    //
+	// This variable points the frontend to the api.
+	// It has to be the full url, including the last /api/v1 part and port.
+	// You can change this if your api is not reachable on the same port as the frontend.
+	window.API_URL = 'http://localhost:8080/api/v1'
+    //
+</script>
 </body>
 </html>