transmission: fix missing optional dependencies

(cherry picked from commit 37134b6072dd01e55f12a8c3a501f7969398a808)

pkgs/applications/networking/p2p/transmission/default.nix

@@ -10,6 +10,11 @@
 , systemd
 , zlib
 , pcre
+, libb64
+, libutp
+, miniupnpc
+, dht
+, libnatpmp
   # Build options
 , enableGTK3 ? false
 , gtk3
@@ -69,6 +74,11 @@ in stdenv.mkDerivation {
     libevent
     zlib
     pcre
+    libb64
+    libutp
+    miniupnpc
+    dht
+    libnatpmp
   ]
   ++ lib.optionals enableQt [ qt5.qttools qt5.qtbase ]
   ++ lib.optionals enableGTK3 [ gtk3 xorg.libpthreadstubs ]
@@ -123,7 +133,7 @@ in stdenv.mkDerivation {
         * Full encryption, DHT, and PEX support
     '';
     homepage = "http://www.transmissionbt.com/";
-    license = lib.licenses.gpl2; # parts are under MIT
+    license = lib.licenses.gpl2Plus; # parts are under MIT
     maintainers = with lib.maintainers; [ astsmtl vcunat wizeman ];
     platforms = lib.platforms.unix;
   };