pgsql: Fix PGDATAOLD and PGDATANEW to properly set pgconfig location, p

Fix PGDATAOLD and PGDATANEW to properly set pgconfig location, per
report from Tom.

Backpatch to 9.2.

Branch
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master

Details
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http://git.postgresql.org/pg/commitdiff/2eeb5eb23fa9ad1a2d636bbf2fd68e6709848d23

Modified Files
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contrib/pg_upgrade/option.c | 23 ++++++++++++++---------
1 files changed, 14 insertions(+), 9 deletions(-)