pgsql: Revert "Document that Python 2.3 requires cdecimal module for fu

Revert "Document that Python 2.3 requires cdecimal module for full functionality."

This reverts commit a8ee81822e43120e1b31949b07af1adadcbeffc1.
The change requiring cdecimal is new in 9.4 (see 7919398bac),
so we should not claim previous branches need it.

Branch
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REL9_2_STABLE

Details
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http://git.postgresql.org/pg/commitdiff/952f0153f3d69927947f8bdcba5d451a2b20e443

Modified Files
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doc/src/sgml/installation.sgml |    8 ++------
1 file changed, 2 insertions(+), 6 deletions(-)