samba: fix broken tarball URLs

Samba and cifs-utils source tarballs have been silently moved to
https://download.samba.org/ without redirects.

pkgs/by-name/ci/cifs-utils/package.nix

@@ -19,7 +19,7 @@ stdenv.mkDerivation rec {
   version = "7.1";
 
   src = fetchurl {
-    url = "mirror://samba/pub/linux-cifs/cifs-utils/${pname}-${version}.tar.bz2";
+    url = "https://download.samba.org/pub/linux-cifs/cifs-utils/${pname}-${version}.tar.bz2";
     sha256 = "sha256-ohEj92pKajbJZTGJukkY6988/NP5CScwpH/zRQtbWyo=";
   };
 

pkgs/servers/samba/4.x.nix

@@ -68,7 +68,7 @@ stdenv.mkDerivation (finalAttrs: {
   version = "4.20.4";
 
   src = fetchurl {
-    url = "mirror://samba/pub/samba/stable/samba-${finalAttrs.version}.tar.gz";
+    url = "https://download.samba.org/pub/samba/stable/samba-${finalAttrs.version}.tar.gz";
     hash = "sha256-OpLpfq6zRbazIjL1A+FNNPA6eqZMRR/owlihG72pCOU=";
   };