New failures in test_x509req.rb

The rewrite of PKCS10 support by @matthauck causes two failures:

```
  1) Failure:
test_sign_and_verify(OpenSSL::TestX509Request) [test/externals/ruby1.9/openssl/test_x509req.rb:108]:
<false> expected but was
<true>.

  1) Failure:
test_version(OpenSSL::TestX509Request) [test/externals/ruby1.9/openssl/test_x509req.rb:42]:
<1> expected but was
<0>.
```
