libvncclient: tls_openssl: fix connection setup w/ newer LibreSSL

This needs the security level setting as well.

re bk138/multivnc#245

Author: bk138

src/libvncclient/tls_openssl.c

@@ -329,7 +329,8 @@ open_ssl_connection (rfbClient *client, int sockfd, rfbBool anonTLS, rfbCredenti
   } else { /* anonTLS here */
       /* Need anonymous ciphers for anonTLS, see https://github.com/LibVNC/libvncserver/issues/347#issuecomment-597477103 */
       SSL_CTX_set_cipher_list(ssl_ctx, "aNULL");
-#if OPENSSL_VERSION_NUMBER >= 0x10100000L && !defined LIBRESSL_VERSION_NUMBER
+#if OPENSSL_VERSION_NUMBER >= 0x10100000L || \
+    (defined (LIBRESSL_VERSION_NUMBER) && LIBRESSL_VERSION_NUMBER >= 0x30600000)
       /*
 	See https://www.openssl.org/docs/man1.1.0/man3/SSL_set_security_level.html
 	Not specifying 0 here makes LibVNCClient fail connecting to some servers.