pgsql: Remove extra semicolon in example

Remove extra semicolon in example

Reported-By: Pavel Luzanov <p.luzanov@postgrespro.ru>
Discussion: /messages/by-id/175976566145.768.4645962241073007347@wrigleys.postgresql.org
Backpatch-through: 18

Branch
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master

Details
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https://git.postgresql.org/pg/commitdiff/e062af861b453769ccf3940fe7920a87d7d31fe6

Modified Files
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doc/src/sgml/func/func-json.sgml | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)