pgsql: Reset the proper GUC in create_index test.

Reset the proper GUC in create_index test.

Thinko in commit a4523c5aa. It doesn't really affect anything at
present, but it would be a problem if any tests added later in this
file ought to get index-only-scan plans. Back-patch, like the previous
commit, just to avoid surprises in case we add such a test and then
back-patch it.

Nikita Glukhov

Discussion: https://postgr.es/m/8b70135d-ad38-bdd8-ac92-71e2b3c273cf@postgrespro.ru

Branch
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REL9_5_STABLE

Details
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http://git.postgresql.org/pg/commitdiff/b60f9820fbc1ee9d5a74269c6a152527de841a17

Modified Files
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src/test/regress/expected/create_index.out | 2 +-
src/test/regress/sql/create_index.sql | 2 +-
2 files changed, 2 insertions(+), 2 deletions(-)