tdm: Fix the build
tdm: Fix the build

Was failing in the desktop-file validation stage [0]:
/nix/store/XXX-tdm.desktop/share/applications/tdm.desktop: error: value
"False" for boolean key "Terminal" in group "Desktop Entry" contains
invalid characters, boolean values must be "false" or "true"

[0]: https://hydra.nixos.org/build/123852137

NixOS/nixpkgs,NixOS/nixpkgs,NixOS/nixpkgs,NixOS/nixpkgs,NixOS/nixpkgs,NixOS/nixpkgs,NixOS/nixpkgs,NixOS/nixpkgs,NixOS/nixpkgs,NixOS/nixpkgs,NixOS/nixpkgs,NixOS/nixpkgs,NixOS/nixpkgs,NixOS/nixpkgs,NixOS/nixpkgs