cmd/derper: increase port 80's WriteTimeout to permit longer CPU profiles

Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>

cmd/derper/derper.go

@@ -233,7 +233,11 @@ func main() {
 				Addr:        net.JoinHostPort(listenHost, "80"),
 				Handler:     certManager.HTTPHandler(tsweb.Port80Handler{Main: mux}),
 				ReadTimeout: 30 * time.Second,
-				WriteTimeout: 30 * time.Second,
+				// Crank up WriteTimeout a bit more than usually
+				// necessary just so we can do long CPU profiles
+				// and not hit net/http/pprof's "profile
+				// duration exceeds server's WriteTimeout".
+				WriteTimeout: 5 * time.Minute,
 			}
 			err := port80srv.ListenAndServe()
 			if err != nil {