pgsql: Add 9.2 release note authorship mentions for Heikki and Alexande

Add 9.2 release note authorship mentions for Heikki and Alexander
Korotkov, per Alexander Korotkov.

Branch
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master

Details
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http://git.postgresql.org/pg/commitdiff/b9c895ee6f336084048f4c8cc76b81afb4535e58

Modified Files
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doc/src/sgml/release-9.2.sgml | 5 +++--
1 files changed, 3 insertions(+), 2 deletions(-)