spice-gtk: update to 0.27

pkgs/development/libraries/spice-gtk/default.nix

···
 with stdenv.lib;
 
 stdenv.mkDerivation rec {
-  name = "spice-gtk-0.25";
+  name = "spice-gtk-0.27";
 
   src = fetchurl {
     url = "http://www.spice-space.org/download/gtk/${name}.tar.bz2";
-    sha256 = "11yh593frbafp0ywkk7pfc2k17q1fwrl8zcjclph3xfr1alccc07";
+    sha256 = "0323j3q7gagi83fvxd7v9vdxqv2s3ziss44ici342hyv21qf0xah";
   };
 
   buildInputs = [