It's not working, I have tried it too. If you figure out please share.
god my answer, its been removed from the masternodeconfig.cpp file of the wallet. the setup reads the following, you will notice it omits the option for donation address unlike what is written in the masternode guide in /docs/
void CMasternodeConfig::add(std::string alias, std::string ip, std::string privKey, std::string txHash, std::string outputIndex)
{
CMasternodeEntry cme(alias, ip, privKey, txHash, outputIndex);
entries.push_back(cme);
}