bug: atlas:txmode requires empty line to parse correctly

works
```sql
-- atlas:txmode none

CREATE INDEX CONCURRENTLY IF NOT EXISTS entity_item_preferred_cohort_vendor_id_index ON entity_item (preferred_cohort_vendor_id);
```

doesn't work
```sql
-- atlas:txmode none
CREATE INDEX CONCURRENTLY IF NOT EXISTS entity_item_preferred_cohort_vendor_id_index ON entity_item (preferred_cohort_vendor_id);
```