Script: Fix two exception messages.
Script: Fix two exception messages.

peterdettman/bitcoinj,natzei/bitcoinj,tangyves/bitcoinj,tangyves/bitcoinj,GroestlCoin/groestlcoinj,kmels/bitcoinj,blockchain/bitcoinj,kmels/bitcoinj,oscarguindzberg/bitcoinj,schildbach/bitcoinj,natzei/bitcoinj,tangyves/bitcoinj,janko33bd/bitcoinj,oscarguindzberg/bitcoinj,bitcoinj/bitcoinj,bitcoinj/bitcoinj,GroestlCoin/groestlcoinj,schildbach/bitcoinj,GroestlCoin/groestlcoinj,yenliangl/bitcoinj,yenliangl/bitcoinj,janko33bd/bitcoinj,peterdettman/bitcoinj