pgsql: C comment: correct heading of extension query

C comment: correct heading of extension query

Reported-by: Justin Pryzby

Discussion: /messages/by-id/20210803161345.GZ12533@telsasoft.com

Backpatch-through: 9.6

Branch
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REL_13_STABLE

Details
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https://git.postgresql.org/pg/commitdiff/47a573d9113e18864dcb637b72ee3ac1a9ec6b5e

Modified Files
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src/bin/pg_upgrade/version.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)