i2pd: enable on all unix platforms, enable parallel build

pkgs/tools/networking/i2pd/default.nix

@@ -20,6 +20,7 @@ stdenv.mkDerivation rec {
 
   buildInputs = with lib; [ boost zlib openssl ]
     ++ optional upnpSupport miniupnpc;
+
   makeFlags =
     let ynf = a: b: a + "=" + (if b then "yes" else "no"); in
     [ (ynf "USE_AESNI" aesniSupport)
@@ -27,6 +28,8 @@ stdenv.mkDerivation rec {
       (ynf "USE_UPNP"  upnpSupport)
     ];
 
+  enableParallelBuilding = true;
+
   installPhase = ''
     install -D i2pd $out/bin/i2pd
   '';
@@ -36,6 +39,6 @@ stdenv.mkDerivation rec {
     description = "Minimal I2P router written in C++";
     license = licenses.bsd3;
     maintainers = with maintainers; [ edwtjo ];
-    platforms = platforms.linux;
+    platforms = platforms.unix;
   };
 }