pgsql: Clean up IPv4 vs IPv6 bogosity in connectFailureMessage().

Clean up IPv4 vs IPv6 bogosity in connectFailureMessage().

Newly added code was supposing that "struct sockaddr_in" applies to IPv6.

Branch
------
master

Details
-------
http://git.postgresql.org/gitweb?p=postgresql.git;a=commitdiff;h=be3b666eb810089fd9a1d42e3888be52ab9ddb63

Modified Files
--------------
src/interfaces/libpq/fe-connect.c | 38 +++++++++++++++++++++++++-----------
1 files changed, 26 insertions(+), 12 deletions(-)