message: Fix cargofmt
diff: @@ -6,9 +6,7 @@ use casper_contract::{
  unwrap_or_revert::UnwrapOrRevert,
  };
  use casper_types::{
  - runtime_args,
  - system::handle_payment,
  - ApiError, Phase, RuntimeArgs, URef, U512,
  + runtime_args, system::handle_payment, ApiError, Phase, RuntimeArgs, URef, U512,
  };
  const ARG_AMOUNT: &str = "amount";
  