Re: docs: note ownership requirement for refreshing materializedviews

Hi Dian,

> On Aug 15, 2018, at 7:46 PM, Dian Fay <dian.m.fay@gmail.com> wrote:
>
> hi all! I discovered today that the REFRESH MATERIALIZED VIEW documentation doesn't mention that only the owner (or a
superuser)may actually perform the refresh operation. This patch adds a note to that effect. 

I played around with this feature a bit and did see this was the case.
Also while playing around I noticed the error message was as such:

    test=> REFRESH MATERIALIZED VIEW blah;
    ERROR: must be owner of relation blah

But it’s not a relation, it’s a materialized view. I attached a patch
that I think should fix this. Kudos to Dave Cramer who was
sitting next to me helping me to locate files and confirm assumptions.

Jonathan