At some point the config flag must have changed from --enable-eme to
--enable-eme=widevine, so it was having no effect.

I was trying to get Spotify to work, when I noticed that drmSupport = true didn't actually enable EME. The Spotify player now loads, but I still don't actually get audio, even though the song appears to be playing. I've tried with and without pulseaudio support in the wrapper.

Motivation for this change

Things done

• Tested using sandboxing
  (nix.useSandbox on NixOS,
  or option build-use-sandbox in nix.conf
  on non-NixOS)
• Built on platform(s)
  • NixOS
  • macOS
  • Linux
• Tested via one or more NixOS test(s) if existing and applicable for the change (look inside nixos/tests)
• Tested compilation of all pkgs that depend on this change using nix-shell -p nox --run "nox-review wip"
• Tested execution of all binary files (usually in ./result/bin/)
• Fits CONTRIBUTING.md.