Fix TSN PubSub sample issue with encoder expectation
Launching udp_rt_pub binary lead to an assertion
udp_rt_pub: /home/gael/Documents/S2OPC/S2OPC/src/PubSub/network/sopc_network_layer.c:667: SOPC_UADP_NetworkMessage_Encode: Assertion `DATASET_LL_DSM_IS_VALID == conf->validFlag`