Remove URL from appdata

Co-authored-by: AsciiWolf <[email protected]>

Author: cengique

Diff for: misc/io.github.grangerhub.Tremulous.appdata.xml

@@ -24,8 +24,7 @@
     <p>
       The GrangerHub version contains the updated game server and
       client binaries with several stability improvements and new
-      features. See the GrangerHub Github page for more details:
-      https://github.com/GrangerHub/tremulous/
+      features. See the homepage for more details.
     </p>
   </description>
   <url type="homepage">https://github.com/GrangerHub/tremulous</url>