Merge #4220

4220: enable separate data output r=disassembler a=disassembler

## Description
This shrinks the linux installer for daedalus.
<!--- A brief description of this PR and the problem is trying to solve -->

## Linked issue
https://iohk.myjetbrains.com/youtrack/issue/CBR-532
<!--- Put here the relevant issue from YouTrack -->



Co-authored-by: Samuel Leathers <[email protected]>

Author: iohk-bors[bot]

nix/iohk-nix-src.json

@@ -1,7 +1,7 @@
 {
   "url": "https://github.com/input-output-hk/iohk-nix",
-  "rev": "05d0b642c5d4a77cd645cc250a658d65e4757aae",
-  "date": "2019-07-09T23:18:02+08:00",
-  "sha256": "17r09fxfir9vcs97vii3jasz49ajkjy77xy0013lab1qkyp72vg6",
+  "rev": "ec5463c3c3442ab3d80500af6c9a57310aed79db",
+  "date": "2019-08-09T20:49:52-04:00",
+  "sha256": "0m1f26awc9v7klzmah06x357hn04bxwyaj287aikjqn2gbg2v51m",
   "fetchSubmodules": false
 }

nix/pkgs.nix

@@ -39,6 +39,7 @@ let
       }
       {
         packages.cardano-sl.patches = [ ./patches/cardano-sl.patch ];
+        packages.ekg-wai.components.library.enableSeparateDataOutput = true;
       }
     ];
   };

nix/update-iohk-nix.sh

@@ -5,5 +5,5 @@ set -euo pipefail
 
 NIX_DIR=$(dirname "$0")
 
-nix-prefetch-git https://github.com/input-output-hk/iohk-nix \
+nix-prefetch-git https://github.com/input-output-hk/iohk-nix refs/heads/haskell-nix-cardano-sl \
                  > "$NIX_DIR/iohk-nix-src.json"