doc: Fix example with database regexp in HBA documentation

This HBA entry was using "local" while specifying an address, which was
incorrect.  While in it, this adjusts the format of the entry to be
aligned with the surroundings.

Oversight in 8fea868.

Reported-by: Stéphane Schildknecht
Reviewed-by: David G. Johnston
Discussion: https://postgr.es/m/44662001-54c4-4bfd-be93-35e01ca25fa1@gmail.com
Backpatch-through: 16

Author: michaelpq

doc/src/sgml/client-auth.sgml

@@ -810,12 +810,11 @@ host    all             all             ::1/128                 trust
 host    all             all             localhost               trust
 
 # The same using a regular expression for DATABASE, that allows connection
-# to the database db1, db2 and any databases with a name beginning with "db"
-# and finishing with a number using two to four digits (like "db1234" or
-# "db12").
+# to any databases with a name beginning with "db" and finishing with a
+# number using two to four digits (like "db1234" or "db12").
 #
-# TYPE  DATABASE                   USER            ADDRESS          METHOD
-local   db1,"/^db\d{2,4}$",db2     all             localhost        trust
+# TYPE  DATABASE        USER            ADDRESS                 METHOD
+host    "/^db\d{2,4}$"  all             localhost               trust
 
 # Allow any user from any host with IP address 192.168.93.x to connect
 # to database "postgres" as the same user name that ident reports for