Properly initialize value of task_dist in job request.

src/api/init_msg.c

@@ -61,6 +61,7 @@ void slurm_init_job_desc_msg(job_desc_msg_t * job_desc_msg)
 	job_desc_msg->exc_nodes   = NULL;
 	job_desc_msg->script      = NULL;
 	job_desc_msg->shared      = (uint16_t) NO_VAL;
+	job_desc_msg->task_dist   = (uint16_t) NO_VAL;
 	job_desc_msg->time_limit  = NO_VAL;
 	job_desc_msg->num_procs   = NO_VAL;
 	job_desc_msg->max_nodes   = NO_VAL;