szip: fix url (previous ftp is now private)

pkgs/development/libraries/szip/default.nix

···
   name = "szip-${version}";
   version = "2.1.1";
   src = fetchurl {
-    url = "ftp://ftp.hdfgroup.org/lib-external/szip/${version}/src/szip-${version}.tar.gz";
-    sha256 = "1a8415a7xifagb22aq9dmy7b2s5l0y6diany3b4qigylw6adlzc9";
+    url = "https://support.hdfgroup.org/ftp/lib-external/szip/${version}/src/szip-${version}.tar.gz";
+    sha256 = "04nlhkzzf1gihvrfbzc6rq4kc13p92ly39dzrb4y4jrd9y5rbvi1";
   };
 
   meta = {