Fix memory leaks
Fix memory leaks

 - fix memory leak on exception in Key::SignCompact()
   (see also 6f21e73 of the bitcoin repo)
 - fix memory leak in CKey::SetCompactSignature()
   (see also 27e35bf of the bitcoin repo)

redfish64/nomiccoin,Magicking/neucoin,NeuCoin/neucoin,Magicking/neucoin,NeuCoin/neucoin,redfish64/nomiccoin,Magicking/neucoin,redfish64/nomiccoin,redfish64/nomiccoin,redfish64/nomiccoin,NeuCoin/neucoin,NeuCoin/neucoin,Magicking/neucoin,redfish64/nomiccoin