pgsql: Default to integer timestamps being off until 8.4, to correspond

Log Message:
-----------
Default to integer timestamps being off until 8.4, to correspond
to the settings used for other platforms.

Modified Files:
--------------
pgsql/src/tools/msvc:
config.pl (r1.6 -> r1.7)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/tools/msvc/config.pl?r1=1.6&r2=1.7)