Protocol compatibility fix.

src/slurmdbd/slurmdbd.c

@@ -605,6 +605,8 @@ static int _send_slurmctld_register_req(slurmdb_cluster_rec_t *cluster_rec)
 		slurm_msg_t_init(&out_msg);
 		out_msg.msg_type = ACCOUNTING_REGISTER_CTLD;
 		out_msg.flags = SLURM_GLOBAL_AUTH_KEY;
+		out_msg.protocol_version
+			= slurmdbd_translate_rpc(cluster_rec->rpc_version);
 		slurm_send_node_msg(fd, &out_msg);
 		/* We probably need to add matching recv_msg function
 		 * for an arbitray fd or should these be fire