[krbdev.mit.edu #6893] error codes from error responses can be discarded when there's e-data

[Greg Hudson via RT]

Are you actually seeing unframed KRB-ERROR responses with e_data?  If so, 
from what server, and what's in the e_data?

The intention of the code is to work around the specific interoperability 
bug where an AD server returns an unframed KRB-ERROR message with no 
e_data, which was a specific observed behavior.  If there are servers 
returning unframed KRB-ERROR messages with e_data, we need to figure out 
how to process it.  The current code intentionally treats the packet as 
garbage (because plen is wrong and the circumstances don't meet the 
specific interop workaround).