gnupg: 2.1.22 -> 2.1.23

This release in a RC for gnupg-2.2. The main difference as far as
nixpkgs is concerned is that the binary `gpg2` is now called `gpg` and
`gpgv2` is called `gpgv`.

This update fixed all explicit use of `gpg2` and `gpgv2` across nixpkgs,
but there might be some packaged software that internally use `gpg2`
not handeled by this commit.

See http://lists.gnu.org/archive/html/info-gnu/2017-08/msg00001.html
for full release information

pkgs/tools/misc/pipelight/pipelight.patch

@@ -62,7 +62,7 @@ diff -urN pipelight.old/configure pipelight.new/configure
 -	gpg_exec="/usr/bin/gpg"
 -fi
 +bash_interp=bash
-+gpg_exec=gpg2
++gpg_exec=gpg
  moz_plugin_path=""
  gcc_runtime_dlls=""
  so_mode="0644"