extend lenient-option-parsing
Extend lenient-option-parsing to allow broken "user-class-data" option (15)
parsing. Where the client encodes encapsulated suboptions wrongly and sends
(option-code)(option-len)(payload) instead of
(option-code)(option-len)(payload-len)(payload), causing the packet to be dropped and the following message to be generated.
DEBUG A_BUFFER6_RECEIVE_UNPACK_FAILED failed to parse query from ? to ?, received over interface ?, reason: incomplete wire-format name