Fix NameError in the exception handler.
Fix NameError in the exception handler.

See also https://github.com/CounterpartyXCP/counterparty-lib/issues/1084 .

Signed-off-by: Cryptcoin Junkey <0e5a31227accb3fbf642c5829b5af4bc4b83b118@gmail.com>

monaparty/counterparty-lib,monaparty/counterparty-lib