refactor: change link to generic UI

Author: danielpeintner

services/introduction.md

@@ -18,7 +18,7 @@ Playground is a tool to validate TDs and manipulate them for usage in other tool
 
 Using the tools below, you can interact with different WoT Things over your browser.
 
-* [Browserified node-wot](http://plugfest.thingweb.io/webui/): You can try interacting with different Things using this simple interface. Note that this is just a demo page to showcase the [browser bundle of node-wot](https://github.com/eclipse-thingweb/node-wot/tree/master/packages/browser-bundle).
+* [Browserified node-wot](https://thingweb.io/webui/): You can try interacting with different Things using this simple interface. Note that this is just a demo page to showcase the [browser bundle of node-wot](https://github.com/eclipse-thingweb/node-wot/tree/master/packages/browser-bundle).
 * [WoT-FXUI](https://github.com/danielpeintner/wot-fxui): JavaFX-based UI to interact with Things (runnable as Web application, local desktop application or as an Android/iOS app).
 
 ## Online Things for Testing