pgsql: doc: Fix example with database regexp in HBA documentation

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 8fea86830e1d.

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

Branch
------
REL_16_STABLE

Details
-------
https://git.postgresql.org/pg/commitdiff/75714e7cae82d7aa2f85fc9c0dde62fd8a771ed5

Modified Files
--------------
doc/src/sgml/client-auth.sgml | 9 ++++-----
1 file changed, 4 insertions(+), 5 deletions(-)