kopia-ui: fix desktop icon not showing (#447225)

Changed files
+1 -1
pkgs
by-name
ko
kopia-ui
+1 -1
pkgs/by-name/ko/kopia-ui/package.nix
···
type = "Application";
desktopName = "KopiaUI";
comment = "Fast and secure open source backup.";
-
icon = "kopia-ui";
+
icon = "kopia";
exec = "kopia-ui";
categories = [ "Utility" ];
})