R hangs on exit if WiFi uses a captive portal and not logged in

[cbogart]

For example on a plane or coffee shop if there's wifi and you haven't paid for it.

Probably either make.socket or write.socket are hanging instead of failing.
Reported here: https://discuss.ropensci.org/t/r-package-authors-may-i-interview-you/178/7?u=cbogart