pgsql: doc: improve ALTER TABLE "offical constraint" wording

doc: improve ALTER TABLE "offical constraint" wording

Reported-by: Josh Kupershmidt

Discussion: /messages/by-id/CAK3UJRF=KY_nx_TRQq+t6jOrtS2rry79ktkzPiMDhFx_K=dZAg@mail.gmail.com

Author: Josh Kupershmidt

Backpatch-through: master

Branch
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master

Details
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https://git.postgresql.org/pg/commitdiff/712dc2338b23196edd94619f43f24d23139cc0a9

Modified Files
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doc/src/sgml/ref/alter_table.sgml | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)