Add https://ultraschall.fm/ to whitelist

As it seems to work, generally.

Author: frans-ebu

.github/workflows/ci.yml

@@ -21,7 +21,7 @@ jobs:
     - name: Install gem
       run: gem install awesome_bot
     - name: Check links
-      run: awesome_bot README.md --skip-save-results --white-list ebu.io/opensource,github.com/ebu/dash.js,github.com/ebu/cpa-auth-provider,github.com/sony/nmos-cpp,netflixtechblog.com/,projects.blender.org/blender/blender,www.kamailio.org/,www.videolan.org/projects/dvblast.html
+      run: awesome_bot README.md --skip-save-results --white-list ebu.io/opensource,github.com/ebu/dash.js,github.com/ebu/cpa-auth-provider,github.com/sony/nmos-cpp,netflixtechblog.com/,projects.blender.org/blender/blender,www.kamailio.org/,ultraschall.fm/,www.videolan.org/projects/dvblast.html
 
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