pgsql: Comment out autovacuum_worker_slots in postgresql.conf.sample.

Comment out autovacuum_worker_slots in postgresql.conf.sample.

All settings in this file should be commented out.  In addition to
fixing that, also fix the indentation for this line.

Oversight in commit c758119e5b.

Reported-by: Daniel Gustafsson <daniel@yesql.se>
Author: Daniel Gustafsson <daniel@yesql.se>
Discussion: https://postgr.es/m/19727040-3EE4-4719-AF4F-2548544113D7%40yesql.se
Backpatch-through: 18

Branch
------
master

Details
-------
https://git.postgresql.org/pg/commitdiff/478c4814a05262c0312c813bf393c4736d76f3f9

Modified Files
--------------
src/backend/utils/misc/postgresql.conf.sample | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)