BUILD: ssl: get0_verified chain is available on libreSSL

Define HAVE_SSL_get0_verified_chain when it's using libreSSL >= 3.3.6.

Author: wlallemand

include/haproxy/openssl-compat.h

@@ -90,6 +90,10 @@
 
 #if (HA_OPENSSL_VERSION_NUMBER >= 0x10101000L)
 #define HAVE_SSL_KEYLOG
+#endif
+
+/* minimum OpenSSL 1.1.1 & libreSSL 3.3.6 */
+#if (defined(LIBRESSL_VERSION_NUMBER) && (LIBRESSL_VERSION_NUMBER >= 0x3030600L)) || (HA_OPENSSL_VERSION_NUMBER >= 0x10101000L)
 #define HAVE_SSL_get0_verified_chain
 #endif