Fix frei0r url

pkgs/development/libraries/frei0r/default.nix

···
   version = "1.4";
 
   src = fetchurl {
-    url = "https://files.dyne.org/frei0r/releases/frei0r-plugins-1.4.tar.gz";
+    url = "https://files.dyne.org/frei0r/releases/${name}.tar.gz";
     sha256 = "0mxyhdp1p1a3ga8170ijygb870zwbww1dgp3kdr1nd4zvsmzqw44";
   };