mbuffer: update to version 20160613

pkgs/tools/misc/mbuffer/default.nix

···
  } :
 
 stdenv.mkDerivation rec {
-  version = "20151002";
+  version = "20160613";
   name = "mbuffer-${version}";
 
   src = fetchurl {
     url = "http://www.maier-komor.de/software/mbuffer/mbuffer-${version}.tgz";
-    sha256 = "04pz70jr7fkdyax7b67g9jr0msl6ff2i8s6fl8zginqz5rrxckqk";
+    sha256 = "1za9yqfn23axnp4zymdsrjkqcci3wxywqw3bv4dxms57q1ljiab7";
   };
 
   buildInputs = [ openssl ];