pgsql: Revert "Prevent incorrect updates of pg_index while reindexing p

Revert "Prevent incorrect updates of pg_index while reindexing pg_index itself."

This reverts commit 8835284e0d903156632f76eea941cf5c592717ec of 2011-04-15.
There's a better way to do it, which will follow shortly.

Branch
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REL8_4_STABLE

Details
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http://git.postgresql.org/pg/commitdiff/1f0ad40656fc0cca935cd20038064e6281a55d30

Modified Files
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src/backend/catalog/index.c |   67 +++++++++++++------------------------------
1 files changed, 20 insertions(+), 47 deletions(-)