pgsql: Fix XML id to match containing page

Fix XML id to match containing page

This was apparently a typo when this part of the documentation was
first added.

Branch
------
master

Details
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https://git.postgresql.org/pg/commitdiff/4220e5721a27286aab726e87d3db5d1ee475fe23

Modified Files
--------------
doc/src/sgml/logical-replication.sgml | 2 +-
doc/src/sgml/logicaldecoding.sgml     | 2 +-
doc/src/sgml/ref/alter_table.sgml     | 2 +-
doc/src/sgml/ref/psql-ref.sgml        | 2 +-
4 files changed, 4 insertions(+), 4 deletions(-)