remove command flag

from review comment:

Let's remove the command line option and make configuration available only through config file and ContourConfiguration CRD.

The command line options currently are a bit of a mess, so we previously agreed to avoid introducing new options there unless absolutely necessary.

Signed-off-by: Geoff Macartney <geoff.macartney@sky.uk>

cmd/contour/serve.go

@@ -126,7 +126,6 @@ func registerServe(app *kingpin.Application) (*kingpin.CmdClause, *serveContext)
 
 	serve.Flag("accesslog-format", "Format for Envoy access logs.").PlaceHolder("<envoy|json>").StringVar((*string)(&ctx.Config.AccessLogFormat))
 
-	serve.Flag("compression", "Set or disable compression type in default Listener filters.").PlaceHolder("<gzip|brotli|zstd|disabled>").StringVar((*string)(&ctx.Config.Compression.Algorithm))
 	serve.Flag("config-path", "Path to base configuration.").Short('c').PlaceHolder("/path/to/file").Action(parseConfig).ExistingFileVar(&configFile)
 	serve.Flag("contour-cafile", "CA bundle file name for serving gRPC with TLS.").Envar("CONTOUR_CAFILE").StringVar(&ctx.caFile)
 	serve.Flag("contour-cert-file", "Contour certificate file name for serving gRPC over TLS.").PlaceHolder("/path/to/file").Envar("CONTOUR_CERT_FILE").StringVar(&ctx.contourCert)