pgsql: dblink docs: fix typo to use "connname" (3 n's), not "conname"

dblink docs:  fix typo to use "connname" (3 n's), not "conname"

This makes the parameter names match the documented prototype names.

Report by Erwin Brandstetter

Backpatch through 9.0

Branch
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REL9_2_STABLE

Details
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http://git.postgresql.org/pg/commitdiff/5690c13ca0887a7828d933323ee4faf2a6409b8f

Modified Files
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doc/src/sgml/dblink.sgml |   26 +++++++++++++-------------
1 file changed, 13 insertions(+), 13 deletions(-)