pgsql: Remove duplicate words in docs and code comments.

Remove duplicate words in docs and code comments.

Additionally, add a missing "the" in a couple of places.

Author: Vignesh C, Dagfinn Ilmari Mannsåker
Discussion: http://postgr.es/m/CALDaNm28t+wWyPfuyqEaARS810Je=dRFkaPertaLAEJYY2cWYQ@mail.gmail.com

Branch
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master

Details
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https://git.postgresql.org/pg/commitdiff/7cc2f59dd57ab275497ae42a4f98e7936e1e3723

Modified Files
--------------
.cirrus.star                              | 2 +-
contrib/citext/expected/citext_utf8.out   | 2 +-
contrib/citext/expected/citext_utf8_1.out | 2 +-
contrib/citext/sql/citext_utf8.sql        | 2 +-
doc/src/sgml/logical-replication.sgml     | 2 +-
doc/src/sgml/ref/create_subscription.sgml | 2 +-
src/backend/access/nbtree/nbtsearch.c     | 4 ++--
src/backend/access/transam/xlogreader.c   | 2 +-
src/backend/executor/nodeHashjoin.c       | 2 +-
src/test/regress/expected/tuplesort.out   | 4 ++--
src/test/regress/sql/tuplesort.sql        | 4 ++--
11 files changed, 14 insertions(+), 14 deletions(-)