Print a warning if an invalid -x option is passed

[Sebastian Schmidt]

Hi,

btlejack currently falls back to -x pcap if an invalid option for -x is passed. It just took me a while to realize that I had typed ll_pcap rather than ll_phdr, and btlejack bailing an error (or printing a warning; but that would probably scroll out of sight easily) in that case would be nice.

Thanks,
Sebastian

[Damien Cauquil]

Fixed in version 2.0, only available on github for now.