Add usage for specifying another host
Add usage for specifying another host

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