Fix flaky gossip ping test

[jstarry]

Problem

Randomly generated socket addresses in the gossip ping test sometimes get generated with port 0 which causes packets to be discarded and the test to fail

Summary of Changes

Skip generated socket addresses with port 0

Fixes #

[jstarry]

Failed test: https://buildkite.com/anza/agave/builds/20074#01956847-51d0-4db5-a5c1-d3253de8aa33

[mergify]

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