back to btc signed message prefix for compatibility
back to btc signed message prefix for compatibility


Former-commit-id: 839450f7fa0be9e4cb2797e28e2332bf156ebf0f
syscoin/syscoin,syscoin/syscoin,syscoin/syscoin2,syscoin/syscoin2,syscoin/syscoin2,syscoin/syscoin,syscoin/syscoin,syscoin/syscoin2,syscoin/syscoin,syscoin/syscoin2,syscoin/syscoin,syscoin/syscoin,syscoin/syscoin2,syscoin/syscoin