pyof is failing to unpack a certain OFPT_ERROR

[viniarck]

If the payload mentioned in this issue were to be sent: kytos-ng/flow_manager#159

It's failing to unpack it:

2023-07-26 11:13:54,522 - ERROR [kytos.napps.kytos/of_core] [main.py:333:on_raw_in] (MainThread) UBInt16(2600) is not a valid GenericFailedCode

pyof an of_core should,t result in this error when trying to unpack it. Good thing that once flow_manager start also validating, then this issue shouldn't happen, but still, it's an underlying issue on pyof too.