Fix from review

Author: embhorn

src/mqtt_socket.c

@@ -437,10 +437,11 @@ int MqttSocket_Connect(MqttClient *client, const char* host, word16 port,
             if (!(client->flags & MQTT_CLIENT_FLAG_IS_DTLS)) {
                 client->tls.ctx = wolfSSL_CTX_new(wolfSSLv23_client_method());
             }
+    #ifdef WOLFSSL_DTLS
             else {
                 client->tls.ctx = wolfSSL_CTX_new(wolfDTLSv1_2_client_method());
             }
-
+    #endif
             if (client->tls.ctx == NULL) {
                 rc = MQTT_CODE_ERROR_TLS_CONNECT;
                 goto exit;