adding port 0 call to validNets listen test
adding port 0 call to validNets listen test

ankushagarwal/cloudsql-proxy,GoogleCloudPlatform/cloud-sql-proxy,GoogleCloudPlatform/cloud-sql-proxy,digiexchris/cloudsql-proxy,ankushagarwal/cloudsql-proxy,pdecat/cloudsql-proxy,digiexchris/cloudsql-proxy,pdecat/cloudsql-proxy