Adding GPA, The GNU Privacy Assistant.

(cherry picked from commit 24a89c028a0d2988805b17f4c69c3f2b3a284b1f)

pkgs/applications/misc/gpa/default.nix

···
+{ stdenv, fetchurl, intltool, pkgconfig, gtk, gpgme, libgpgerror, libassuan }:
+
+stdenv.mkDerivation rec {
+  
+  name = "gpa-0.9.7";
+
+  src = fetchurl {
+    url = "ftp://ftp.gnupg.org/gcrypt/gpa/${name}.tar.bz2";
+    sha256 = "1r8pnvfw66b2m9lhajlarbxx9172c1gzripdij01bawgbrhwp33y";
+  };
+
+  buildInputs = [ intltool pkgconfig gtk gpgme libgpgerror libassuan ];
+
+  meta = with stdenv.lib; {
+    description = "Graphical user interface for the GnuPG";
+    homepage = https://www.gnupg.org/related_software/gpa/;
+    license = licenses.gpl3Plus;
+    platforms = platforms.linux;
+  };
+}

pkgs/top-level/all-packages.nix

···
 
   google-musicmanager = callPackage ../applications/audio/google-musicmanager { };
 
+  gpa = callPackage ../applications/misc/gpa { };
+
   gpicview = callPackage ../applications/graphics/gpicview { };
 
   gqrx = callPackage ../applications/misc/gqrx { };