python.pkgs.recaptcha-client: disable broken versions

It seems that the recaptcha-client package is no longer maintained.

* The latest released version (1.0.6) is from the year 2011;
* The project page does not mention which Python versions are supported
* The project is hosted on google code, which is discontinued

I was able to succesfully build with Python versions 3.3, 3.4, but not
3.5, 3.6.

pkgs/top-level/python-packages.nix

···
       sha256 = "28c6853c1d13d365b7dc71a6b05e5ffb56471f70a850de318af50d3d7c0dea2f";
     };
 
+    disabled = isPy35 || isPy36;
+
     meta = {
       description = "A CAPTCHA for Python using the reCAPTCHA service";
       homepage = http://recaptcha.net/;