Обсуждение: pgsql: Fix comment.

Fix comment.

This comment was copy-pasted from nodeAppend.c to nodeMergeAppend.c, but
while committing 5220bb7533, I modified wrong copy of it.

Spotted by David Rowley

Branch
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master

Details
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https://git.postgresql.org/pg/commitdiff/405cb356d6104eccf34acc2e4944d711b0961c7d

Modified Files
--------------
src/backend/executor/nodeAppend.c      | 2 +-
src/backend/executor/nodeMergeAppend.c | 2 +-
2 files changed, 2 insertions(+), 2 deletions(-)