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
------
REL9_1_STABLE

Details
-------
http://git.postgresql.org/pg/commitdiff/885604d112d5b20d94e2d5d8b352d47a6e585ceb

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