[COMMITTERS] pgsql: Add missing documentation for effective_io_concurrencytablespac

Add missing documentation for effective_io_concurrency tablespace option.

The description of effective_io_concurrency option was missing in ALTER
TABLESPACE docs though it's included in CREATE TABLESPACE one.

Back-patch to 9.6 where effective_io_concurrency tablespace option was added.

Michael Paquier, reported by Marc-Olaf Jaschke

Branch
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master

Details
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http://git.postgresql.org/pg/commitdiff/4e344c2cf4ff00ca38ea0035bc137dab95fdd0c0

Modified Files
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doc/src/sgml/ref/alter_tablespace.sgml | 17 +++++++++--------
1 file changed, 9 insertions(+), 8 deletions(-)