Documentaion fix.

Hello.

I found that an example output in the following page is not
correct for the version.

https://www.postgresql.org/docs/10/static/warm-standby.html

postgres=# SELECT * FROM pg_replication_slots;
> slot_name | slot_type | datoid | database | active | xmin | restart_lsn | confirmed_flush_lsn
> -------------+-----------+--------+----------+--------+------+-------------+---------------------
> node_a_slot | physical | | | f | | |

The correct one is

> slot_name | plugin | slot_type | datoid | database | temporary | active | active_pid | xmin | catalog_xmin | restart_lsn | confirmed_flush_lsn
> -------------+--------+-----------+--------+----------+-----------+--------+------------+------+--------------+-------------+---------------------
> node_a_slot | | physical | | | f | f | | | | |

From 9.4, 9.5, 9.6 and 10 and later have an example output wrong
in individual way of the version. I'm not sure how the
documentation was updated but each of the attached patches fixes
the version designated in the file name.

But, just fixing it makes the line seemingly a bit too long..

regards.

--
Kyotaro Horiguchi
NTT Open Source Software Center