message: [web] extend web client timeout
  RCP with USB transport needs more time for reinitialization after
  hard resetting due to reattaching the USB device to host OS.
diff: @@ -283,7 +283,7 @@ bool OpenThreadClient::FactoryReset(void)
  Execute("factoryreset");
  signal(SIGPIPE, handler);
  Disconnect();
  - sleep(1);
  + sleep(4);
  VerifyOrExit(rval = Connect());
  result = Execute("version");
  