pgsql: Sync 8.1 pg_config.h.in with expected autoheader output (looks

Log Message:
-----------
Sync 8.1 pg_config.h.in with expected autoheader output (looks like
someone did this manually last time ...)

Tags:
----
REL8_1_STABLE

Modified Files:
--------------
pgsql/src/include:
pg_config.h.in (r1.87.2.3 -> r1.87.2.4)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/include/pg_config.h.in.diff?r1=1.87.2.3&r2=1.87.2.4)