Updated nginx to 1.4.2 and naxsi to 0.51

Changes with nginx 1.4.2

    *) Bugfix: the $r->header_in() embedded perl method did not return value
      of the "Cookie" and "X-Forwarded-For" request header lines; the bug
      had appeared in 1.3.14.

    *) Bugfix: nginx could not be built with the ngx_mail_ssl_module, but
      without ngx_http_ssl_module; the bug had appeared in 1.3.14.

    *) Bugfix: in the "proxy_set_body" directive.
      Thanks to Lanshun Zhou.

    *) Bugfix: the "fail_timeout" parameter of the "server" directive in the
      "upstream" context might not work if "max_fails" parameter was used;
      the bug had appeared in 1.3.0.

    *) Bugfix: a segmentation fault might occur in a worker process if the
      "ssl_stapling" directive was used.
      Thanks to Piotr Sikora.

    *) Bugfix: nginx/Windows might stop accepting connections if several
      worker processes were used.

(imil)