Litecoin: Update default assume valid, chain work and chaintx values
Litecoin: Update default assume valid, chain work and chaintx values

untrustbank/litecoin,bespike/litecoin,bespike/litecoin,untrustbank/litecoin,bespike/litecoin,untrustbank/litecoin,bespike/litecoin,untrustbank/litecoin,bespike/litecoin,bespike/litecoin,untrustbank/litecoin,untrustbank/litecoin