pgsql: Probe only 127.0.0.1 when looking for ports on Unix.

Probe only 127.0.0.1 when looking for ports on Unix.

Commit c0985099, later adjusted by commit 4ab02e81, probed 0.0.0.0
in addition to 127.0.0.1, for the benefit of Windows build farm
animals.  It isn't really useful on Unix systems, and turned out to
be a bit inconvenient to users of some corporate firewall software.
Switch back to probing just 127.0.0.1 on non-Windows systems.

Back-patch to 9.6, like the earlier changes.

Discussion: https://postgr.es/m/CA%2BhUKG%2B21EPwfgs4m%2BtqyRtbVqkOUvP8QQ8sWk9%2Bh55Aub1H3A%40mail.gmail.com

Branch
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master

Details
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https://git.postgresql.org/pg/commitdiff/8efe710d9c84502b3e6a9487937bccf881f56d9c

Modified Files
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src/test/perl/PostgresNode.pm | 7 ++++---
1 file changed, 4 insertions(+), 3 deletions(-)