pgsql: doc: PG 16 relnotes, adjust subscription origin mention

doc: PG 16 relnotes, adjust subscription origin mention

Reported-by: Masahiko Sawada

Discussion: /messages/by-id/CAD21AoC+VihMWs3-xVB3Z=8LzLbsQc52TO29o25rzfqcnJDCUQ@mail.gmail.com

Branch
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master

Details
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https://git.postgresql.org/pg/commitdiff/f7c16a120cfa550214a14e3f42ce949fdd37ec40

Modified Files
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doc/src/sgml/release-16.sgml | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)