dnscrypt-proxy: 1.7.0 -> 1.9.0

Release notes at:
https://github.com/jedisct1/dnscrypt-proxy/releases/tag/1.9.0

Packaging tweaks:
- No longer split man page, kind of pointless ...
- No longer install libtool files, they are now optional

pkgs/tools/networking/dnscrypt-proxy/default.nix

@@ -1,14 +1,14 @@
-{ stdenv, fetchurl, libsodium, pkgconfig, systemd }:
+{ stdenv, fetchurl, pkgconfig, libsodium, systemd }:
 
 with stdenv.lib;
 
 stdenv.mkDerivation rec {
   name = "dnscrypt-proxy-${version}";
-  version = "1.7.0";
+  version = "1.9.0";
 
   src = fetchurl {
     url = "https://download.dnscrypt.org/dnscrypt-proxy/${name}.tar.bz2";
-    sha256 = "1qw2nib0d5ia8581lbdnjxgn9c7pf2qw8vhpnnh1wjcjj3gpgbqx";
+    sha256 = "0v5rsn9zdakzn6rcf2qhjqfd2y4h8q0hj4xr5hwhvaskg213rsyp";
   };
 
   configureFlags = optional stdenv.isLinux "--with-systemd";
@@ -17,7 +17,19 @@ stdenv.mkDerivation rec {
 
   buildInputs = [ libsodium ] ++ optional stdenv.isLinux systemd;
 
-  outputs = [ "out" "man" ];
+  postInstall = ''
+    # Previous versions required libtool files to load plugins; they are
+    # now strictly optional.
+    rm $out/lib/dnscrypt-proxy/*.la
+
+    # The installation ends up copying the same sample configuration
+    # into $out/etc twice, with the expectation that one of them will be
+    # edited by the user.  Since we can't modify the file, it makes more
+    # sense to move only a single copy to the doc directory.
+    mkdir -p $out/share/doc/dnscrypt-proxy
+    mv $out/etc/dnscrypt-proxy.conf.example $out/share/doc/dnscrypt-proxy/
+    rm -rf $out/etc
+  '';
 
   meta = {
     description = "A tool for securing communications between a client and a DNS resolver";