SSL: let it build against LibreSSL.

LibreSSL developers decided that LibreSSL is OpenSSL-2.0.0, so tests
for OpenSSL-1.0.2+ are now passing, even though the library doesn't
provide functions that are expected from that version of OpenSSL.

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 7ee7775..bb82143 100644
--- a/src/event/ngx_event_openssl.c
+++ b/src/event/ngx_event_openssl.c
@@ -50,7 +50,7 @@
     HMAC_CTX *hctx, int enc);
 #endif
 
-#if OPENSSL_VERSION_NUMBER < 0x10002002L
+#if (OPENSSL_VERSION_NUMBER < 0x10002002L || defined LIBRESSL_VERSION_NUMBER)
 static ngx_int_t ngx_ssl_check_name(ngx_str_t *name, ASN1_STRING *str);
 #endif
 
@@ -2743,7 +2743,7 @@
         return NGX_ERROR;
     }
 
-#if OPENSSL_VERSION_NUMBER >= 0x10002002L
+#if (OPENSSL_VERSION_NUMBER >= 0x10002002L && !defined LIBRESSL_VERSION_NUMBER)
 
     /* X509_check_host() is only available in OpenSSL 1.0.2+ */
 
@@ -2860,7 +2860,7 @@
 }
 
 
-#if OPENSSL_VERSION_NUMBER < 0x10002002L
+#if (OPENSSL_VERSION_NUMBER < 0x10002002L || defined LIBRESSL_VERSION_NUMBER)
 
 static ngx_int_t
 ngx_ssl_check_name(ngx_str_t *name, ASN1_STRING *pattern)