Wrong error message in REINDEX command

Hi,

I got wrong error message when I did REINDEX SYSTEM command in
transaction as follows.
It should say "ERROR:  REINDEX SYSTEM cannot run inside a transaction block"
Attached patch fixes it.

[postgres][5432](1)=# begin;
BEGIN
[postgres][5432](1)=# reindex system postgres;
ERROR:  REINDEX DATABASE cannot run inside a transaction block
STATEMENT:  reindex system postgres;

Regards,

-------
Sawada Masahiko