Curl_rand: Uninitialized variable: r

This is not actually used uninitialized but we silence warnings.

Bug: http://curl.haxx.se/bug/view.cgi?id=1437
Reported-by: Julien
gnutls: removed dead code

Bug: http://curl.haxx.se/bug/view.cgi?id=1437
Reported-by: Julien