Single table views can be used in UPDATE

Hi,

I have a simple table

```
CREATE TABLE test AS
SELECT
generate_series(1,10000000) AS id,
substr(concat(md5(random()::text), md5(random()::text)), 1, (random() * 64)::integer + 1) AS description, false as is_process;
```
and a view
```
create view test_view as select id, is_procesed from test;
```

Now I want to be able to update the view
```
update test_view set is_procesed = true ;
```
But end up with `ERROR: relation test_view is not distributed`

I think it's reasonable for a single table view to allow an update the same way as a table does.