SSL: guard use of SSL_OP_MSIE_SSLV2_RSA_PADDING.

This option had no effect since 0.9.7h / 0.9.8b and it was removed
in recent OpenSSL.

This patch comes from http://hg.nginx.org/nginx/rev/a73678f5f96f.
Merge pull request #459 from chobits/ssl_fix

SSL: fix compilation error: 'SSL_OP_MSIE_SSLV2_RSA_PADDING' undeclared