Fix renegotiation flag for older version of openssl (coturn#978)

`SSL_OP_NO_RENEGOTIATION` is only supported in openssl-1.1.0 and above
Older versions have `SSL3_FLAGS_NO_RENEGOTIATE_CIPHERS `

Fixes coturn#977 and coturn#952

Test:
Build in a docker container running running openssl-1.0.2g (ubuntu
16.04) successfully (without the fix getting the same errors)

src/apps/relay/dtls_listener.c

@@ -295,8 +295,17 @@ static ioa_socket_handle dtls_server_input_handler(dtls_listener_relay_server_ty
 	SSL_set_accept_state(connecting_ssl);
 
 	SSL_set_bio(connecting_ssl, NULL, wbio);
-	SSL_set_options(connecting_ssl, SSL_OP_COOKIE_EXCHANGE | SSL_OP_NO_RENEGOTIATION);
-
+	SSL_set_options(connecting_ssl, SSL_OP_COOKIE_EXCHANGE
+#if OPENSSL_VERSION_NUMBER < 0x10100000L
+#if defined(SSL3_FLAGS_NO_RENEGOTIATE_CIPHERS)
+		| SSL3_FLAGS_NO_RENEGOTIATE_CIPHERS
+#endif
+#else
+#if defined(SSL_OP_NO_RENEGOTIATION)
+		| SSL_OP_NO_RENEGOTIATION
+#endif
+#endif
+	);
 	SSL_set_max_cert_list(connecting_ssl, 655350);
 
 	ioa_socket_handle rc = dtls_accept_client_connection(server, s, connecting_ssl,
@@ -581,7 +590,17 @@ static int create_new_connected_udp_socket(
 
 		SSL_set_bio(connecting_ssl, NULL, wbio);
 
-		SSL_set_options(connecting_ssl, SSL_OP_COOKIE_EXCHANGE | SSL_OP_NO_RENEGOTIATION);
+		SSL_set_options(connecting_ssl, SSL_OP_COOKIE_EXCHANGE
+#if OPENSSL_VERSION_NUMBER < 0x10100000L
+#if defined(SSL3_FLAGS_NO_RENEGOTIATE_CIPHERS)
+			| SSL3_FLAGS_NO_RENEGOTIATE_CIPHERS
+#endif
+#else
+#if defined(SSL_OP_NO_RENEGOTIATION)
+			| SSL_OP_NO_RENEGOTIATION
+#endif
+#endif
+		);
 
 		SSL_set_max_cert_list(connecting_ssl, 655350);
 		int rc = ssl_read(ret->fd, connecting_ssl, server->sm.m.sm.nd.nbh,

src/apps/relay/ns_ioalib_engine_impl.c

@@ -1428,7 +1428,17 @@ static void set_socket_ssl(ioa_socket_handle s, SSL *ssl)
 		if(ssl) {
 			SSL_set_app_data(ssl,s);
 			SSL_set_info_callback(ssl, (ssl_info_callback_t)ssl_info_callback);
-			SSL_set_options(ssl, SSL_OP_NO_RENEGOTIATION);
+			SSL_set_options(ssl, 
+#if OPENSSL_VERSION_NUMBER < 0x10100000L
+#if defined(SSL3_FLAGS_NO_RENEGOTIATE_CIPHERS)
+				SSL3_FLAGS_NO_RENEGOTIATE_CIPHERS
+#endif
+#else
+#if defined(SSL_OP_NO_RENEGOTIATION)
+				SSL_OP_NO_RENEGOTIATION
+#endif
+#endif
+			);
 		}
 	}
 }