message: Simplify nonce to u64
diff: @@ -7,7 +7,7 @@ pub fn verify_transaction<A: Api>(
  api: A,
  from: [u8; 20],
  to: [u8; 20],
  - nonce: u128,
  + nonce: u64,
  gas: u128,
  gas_price: u128,
  value: u128,
  @@ -38,7 +38,7 @@ pub fn verify_transaction<A: Api>(
  fn serialize_unsigned_transaction(
  to: [u8; 20],
  - nonce: u128,
  + nonce: u64,
  gas_limit: u128,
  gas_price: u128,
  value: u128,
  