icu: keep default version on 58

... to avoid mass rebuilds for now. (Bumped in parent merge.)

Changed files
+1 -1
pkgs
top-level
+1 -1
pkgs/top-level/all-packages.nix
···
icu58 = callPackage ../development/libraries/icu/58.nix { };
icu59 = callPackage ../development/libraries/icu/59.nix { };
-
icu = icu59;
+
icu = icu58;
id3lib = callPackage ../development/libraries/id3lib { };