pgsql: Fix grammar in datatype.sgml

Fix grammar in datatype.sgml

Introduced in b139bd3b6ef0.

Reported-by: Man Zeng <zengman@halodbtech.com>
Discussion: /messages/by-id/tencent_121C1BB152CAF3195C99D56C@qq.com

Branch
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master

Details
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https://git.postgresql.org/pg/commitdiff/ba887a8cdb5b4ebaebd7d5c9ce790563659e710e

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