Detect when reader is unplugged rather than busy loop 100% CPU

[doegox]

It would be nice if the client could detect decently when the reader is unplugged (and maybe switch to the offline mode?).
Right now, it just enters a busy loop eating 100% of the CPU.

[uzlonewolf]

Check #516 . Are you running WIN32 or *nix?

[doegox]

Linux, and here your patch is working very well :)

[bruno-]

I'm experiencing the same issue on MacOS.