go profiler should not listen on all endpoints by default

[jholdstock]

Ideally the flag to enable the profiler would be a string so the admin can specify the endpoint, but if using a bool it should listen on loopback interfaces only.

dcrdex/server/cmd/dcrdex/main.go

Lines 72 to 81 in 7789513

	if opts.HTTPProfile {
	log.Warnf("Starting the HTTP profiler on path /debug/pprof/.")
	// http pprof uses http.DefaultServeMux
	http.Handle("/", http.RedirectHandler("/debug/pprof/", http.StatusSeeOther))
	go func() {
	if err := http.ListenAndServe(":9232", nil); err != nil {
	log.Errorf("ListenAndServe failed for http/pprof: %v", err)
	}
	}()
	}