pgsql: Un-break compression of plain-text output format in pg_dump.

Un-break compression of plain-text output format in pg_dump.

pg_dump has historically understood -Z with no -F switch to mean that
it should emit a gzip-compressed version of its plain text output.
This got broken through a misunderstanding in the 9.1 patch that added
directory output format.  Restore the former behavior.

Per complaint from Roger Niederland and diagnosis by Adrian Klaver.

Branch
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REL9_1_STABLE

Details
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http://git.postgresql.org/pg/commitdiff/be64ba6230d697bca724f9c4aaa9f071164364d1

Modified Files
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src/bin/pg_dump/pg_dump.c |   12 +++---------
1 files changed, 3 insertions(+), 9 deletions(-)