pgsql: Fix SSPI login when multiple roundtrips are required

Fix SSPI login when multiple roundtrips are required

This fixes SSPI login failures showing "The function
requested is not supported", often showing up when connecting
to localhost. The reason was not properly updating the SSPI
handle when multiple roundtrips were required to complete the
authentication sequence.

Report and analysis by Ahmed Shinwari, patch by Magnus Hagander

Branch
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REL8_4_STABLE

Details
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http://git.postgresql.org/pg/commitdiff/8aba2807424221f76b51f8d8b54b4ac414171c18

Modified Files
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src/backend/libpq/auth.c |   10 ++++++++--
1 files changed, 8 insertions(+), 2 deletions(-)