pgsql: Fix breakages of hot standby regression test.

Fix breakages of hot standby regression test.

This commit changes HS regression test so that it uses
REPEATABLE READ transaction instead of SERIALIZABLE one
because SERIALIZABLE transaction isolation level is not
available in HS. Also this commit fixes VACUUM/ANALYZE
label mixup.

This was fixed in HEAD (commit 2985e16), but it should
have been back-patched to 9.1 which had introduced SSI
and forbidden SERIALIZABLE transaction in HS.

Amit Langote

Branch
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REL9_2_STABLE

Details
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http://git.postgresql.org/pg/commitdiff/bdc5400bc627e72a1fcf9d61459d0a34db58fca8

Modified Files
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src/test/regress/expected/hs_standby_allowed.out | 2 +-
src/test/regress/expected/hs_standby_disallowed.out | 2 +-
src/test/regress/sql/hs_standby_allowed.sql | 2 +-
3 files changed, 3 insertions(+), 3 deletions(-)