Discard internal "'" character in Relayhost comment of metadata.rb.

This patch allows 'berks upload' in chefdk 3.1.0 to successfully upload on CentOS 6. It seems that the embedded single quote in the word "Relayhost's" confuses creation of the relevant metadata.json and breaks Berkshelf uploads in this environment.

It works fine with librarian-chef, just not Berkshelf.