Revert "Merge pull request #1478 from dsd/fix/master/18781-webrick-old-client-compat"

This reverts commit 86331385e6263bf370a8e42f52f882d43882efd2, reversing
changes made to a10b85bd9e7198ca71ef0461bcdfe5ff75698724.

The commit being reverted causes webrick to be loaded during puppet
startup, e.g. puppet --version, and webrick performs a reverse DNS
lookup of the local IP address, which can cause unnecessary delays.