Please change the alert public key. Generate your own, or set it to "0" to disable it. Otherwise, any networks alerts sent on Supcoin could potentially be broadcast on Voyacoin as well.

Also, it's too late now, but you should have changed the public key prefix (https://github.com/Voyacoin/Voyacoin/blob/master/src/chainparams.cpp#L190) to something else, so that addresses aren't valid on both networks