pgsql: Fix oversight in pg_dump's handling of extension configuration t

Fix oversight in pg_dump's handling of extension configuration tables.

If an extension has not been selected to be dumped (perhaps because of
a --schema or --table switch), the contents of its configuration tables
surely should not get dumped either.  Per gripe from
Hubert Depesz Lubaczewski.

Branch
------
master

Details
-------
http://git.postgresql.org/pg/commitdiff/59de132f9a578ae5d2909228484a61309df986e0

Modified Files
--------------
src/bin/pg_dump/pg_dump.c |    9 +++++++--
1 files changed, 7 insertions(+), 2 deletions(-)