Fix update check URL

UpdateCheck.cs

@@ -11,7 +11,7 @@ internal static class UpdateCheck
 {
     private static UpdateManager _updateManager;
 
-    public static UpdateManager UpdateManager => _updateManager ??= new UpdateManager(new GithubSource("https://github.com/ckaczor/WorkIndicator", null, false));
+    public static UpdateManager UpdateManager => _updateManager ??= new UpdateManager(new GiteaSource("https://gitea.kaczorzoo.net/ckaczor/WorkIndicator", null, false));
 
     public static string LocalVersion => (UpdateManager.CurrentVersion ?? new SemanticVersion(0, 0, 0)).ToString();