pgsql: doc: change "can not" to "cannot"

doc: change "can not" to "cannot"

Reported-by: Chao Li

Author: Chao Li

Discussion: /messages/by-id/CAEoWx2kyiD+7-vUoOYhH=y2Hrmvqyyhm4EhzgKyrxGBXOMWCxw@mail.gmail.com

Branch
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master

Details
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https://git.postgresql.org/pg/commitdiff/41808377fec7e6d5bb80f550f3640a503470da23

Modified Files
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doc/src/sgml/ecpg.sgml | 2 +-
doc/src/sgml/func/func-aggregate.sgml | 4 ++--
2 files changed, 3 insertions(+), 3 deletions(-)