SSL: fixed possible memory and file descriptor leak on HUP signal.

The problem appeared in 386a06a22c40 (1.3.7).

Signed-off-by: Piotr Sikora <piotr@cloudflare.com>

src/event/ngx_event_openssl.c

diff --git a/src/event/ngx_event_openssl.c b/src/event/ngx_event_openssl.c
index fedb604..4bfec9a 100644
--- a/src/event/ngx_event_openssl.c
+++ b/src/event/ngx_event_openssl.c
@@ -280,6 +280,8 @@
     {
         ngx_ssl_error(NGX_LOG_EMERG, ssl->log, 0,
                       "SSL_CTX_set_ex_data() failed");
+        X509_free(x509);
+        BIO_free(bio);
         return NGX_ERROR;
     }