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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REL_10_STABLE

Details
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https://git.postgresql.org/pg/commitdiff/8c7a8e19bb17e0634e21ee8edbb912dc4deb5cb0

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